U.S. patent number 10,517,512 [Application Number 15/211,619] was granted by the patent office on 2019-12-31 for swing diagnosis method, recording medium, swing diagnosis apparatus, and swing diagnosis system.
This patent grant is currently assigned to SEIKO EPSON CORPORATION. The grantee listed for this patent is SEIKO EPSON CORPORATION. Invention is credited to Norihisa Hagiwara, Kazuhiro Ito, Tsuyoshi Ito, Kenya Kodaira.
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United States Patent |
10,517,512 |
Ito , et al. |
December 31, 2019 |
Swing diagnosis method, recording medium, swing diagnosis
apparatus, and swing diagnosis system
Abstract
A swing diagnosis method includes a procedure of calculating
levels of a plurality of items including a first item regarding at
least one of a backswing and a downswing, and a second item
regarding impact on the basis of data regarding a swing, and a
procedure of outputting information regarding the levels of the
plurality of items.
Inventors: |
Ito; Tsuyoshi (Suwa,
JP), Kodaira; Kenya (Azumino, JP),
Hagiwara; Norihisa (Hachioji, JP), Ito; Kazuhiro
(Yokohama, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
SEIKO EPSON CORPORATION |
Tokyo |
N/A |
JP |
|
|
Assignee: |
SEIKO EPSON CORPORATION (Tokyo,
JP)
|
Family
ID: |
57886303 |
Appl.
No.: |
15/211,619 |
Filed: |
July 15, 2016 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20170028282 A1 |
Feb 2, 2017 |
|
Foreign Application Priority Data
|
|
|
|
|
Jul 28, 2015 [JP] |
|
|
2015-148639 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06Q
10/0639 (20130101); A61B 5/1121 (20130101); G09B
19/0038 (20130101); A61B 5/6895 (20130101); A61B
2562/0219 (20130101); A61B 5/7455 (20130101); A61B
2503/10 (20130101); A61B 5/681 (20130101); A61B
5/6824 (20130101); H04M 1/7253 (20130101) |
Current International
Class: |
A63B
69/36 (20060101); A61B 5/11 (20060101) |
Field of
Search: |
;473/594,614,212,221,223,409 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2004-135908 |
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May 2004 |
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JP |
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2005-270500 |
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Oct 2005 |
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JP |
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2008-073210 |
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Apr 2008 |
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JP |
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2014-097104 |
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May 2014 |
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JP |
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2015-002910 |
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Jan 2015 |
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JP |
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2015-002911 |
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Jan 2015 |
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JP |
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2015-002912 |
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Jan 2015 |
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JP |
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2015-009008 |
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Jan 2015 |
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JP |
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2015-013007 |
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Jan 2015 |
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JP |
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2015-073821 |
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Apr 2015 |
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JP |
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2015-073822 |
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Apr 2015 |
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JP |
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2016-013302 |
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Jan 2016 |
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JP |
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2017-023636 |
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Feb 2017 |
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JP |
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2017-023638 |
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Feb 2017 |
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JP |
|
2017-023639 |
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Feb 2017 |
|
JP |
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2017-023640 |
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Feb 2017 |
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JP |
|
2017-023643 |
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Feb 2017 |
|
JP |
|
2017-029460 |
|
Feb 2017 |
|
JP |
|
Primary Examiner: Legesse; Nini F
Attorney, Agent or Firm: Oliff PLC
Claims
What is claimed is:
1. A swing diagnosis method comprising: grading, based on data
regarding a swing, a plurality of items including (i) a first item
regarding at least one of a backswing and a downswing and (ii) a
second item regarding impact; and outputting the grading, wherein
the grading is performed by assigning to each of the first and
second items a score calculated from the data regarding the swing,
the score of the first item is calculated using the first item and
a first score table stored in a memory, and the score of the second
item is calculated using the second item and a second score table
stored in the memory.
2. The swing diagnosis method according to claim 1, wherein the
first item includes an item indicating a relationship between (i) a
position of a ball hitting portion of an exercise appliance at a
first timing during the backswing with respect to at least one
virtual plane and (ii) a position of the ball hitting portion at a
second timing during the downswing with respect to the at least one
virtual plane.
3. The swing diagnosis method according to claim 2, wherein the at
least one virtual plane includes: a first virtual plane that is
specified based on (i) a first axis along a target hit ball
direction and (ii) a second axis along a longitudinal direction of
the exercise appliance before starting the backswing; and a second
virtual plane that forms a first angle with the first virtual
plane.
4. The swing diagnosis method according to claim 1, wherein the
first item includes an item regarding efficiency of the swing.
5. The swing diagnosis method according to claim 4, wherein the
item regarding the swing efficiency is an item indicating a
relationship between a deceleration amount and a deceleration
period of a holding portion of an exercise appliance in the
downswing.
6. The swing diagnosis method according to claim 1, wherein the
second item includes an item indicating a relationship between an
incidence angle of a ball hitting portion of an exercise appliance
and an inclination of the ball hitting portion at impact.
7. The swing diagnosis method according to claim 1, wherein the
second item includes an item regarding a speed of an exercise
appliance at impact.
8. The swing diagnosis method according to claim 1, wherein the
plurality of items include a third item regarding a time at which
the backswing transitions to the downswing and a time of the
impact.
9. The swing diagnosis method according to claim 8, wherein the
third item includes an item indicating a relationship between (i) a
rotation angle about a rotation axis of an exercise appliance at
the time at which the backswing transitions to the downswing, a
longitudinal direction of the exercise appliance being the rotation
axis, and (ii) an inclination of a ball hitting portion of the
exercise appliance at the time of the impact.
10. A non-transitory computer-readable recording medium recording a
swing diagnosis program causing a computer to execute: grading,
based on data regarding a swing, a plurality of items including (i)
a first item regarding at least one of a backswing and a downswing
and (ii) a second item regarding impact; and outputting the
grading, wherein the grading is performed by assigning to each of
the first and second items a score calculated from the data
regarding the swing, the score of the first item is calculated
using the first item and a first score table, and the score of the
second item is calculated using the second item and a second score
table.
11. A swing diagnosis apparatus comprising: a grading calculation
section that grades, based on data regarding a swing, a plurality
of items including (i) a first item regarding at least one of a
backswing and a downswing and (ii) a second item regarding impact;
a memory; and an output section that outputs the grading, wherein
the grading calculation section performs the grading by assigning
to each of the first and second items a score calculated from the
data regarding the swing, the score of the first item is calculated
using the first item and a first score table stored in the memory,
and the score of the second item is calculated using the second
item and a second score table stored in the memory.
12. A swing diagnosis system comprising: the swing diagnosis
apparatus according to claim 11; and an inertial sensor that
measures the swing.
13. A swing diagnosis apparatus comprising a processor configured
to: grade, based on data regarding a swing, a plurality of items
including (i) a first item regarding at least one of a backswing
and a downswing and (ii) a second item regarding impact; a memory;
and output the grading, wherein the score of the first item is
calculated using the first item and a first score table stored in
the memory, and the score of the second item is calculated using
the second item and a second score table stored in the memory.
14. The swing diagnosis apparatus according to claim 13, wherein
the first item includes an item indicating a relationship between
(i) a position of a ball hitting portion of an exercise appliance
at a first timing during the backswing with respect to at least one
virtual plane and (ii) a position of the ball hitting portion at a
second timing during the downswing with respect to the at least one
virtual plane.
15. The swing diagnosis apparatus according to claim 14, wherein
the at least one virtual plane includes: a first virtual plane that
is specified based on (i) a first axis along a target hit ball
direction and (ii) a second axis along a longitudinal direction of
the exercise appliance before starting the backswing; and a second
virtual plane that forms a first angle with the first virtual
plane.
16. The swing diagnosis apparatus according to claim 13, wherein
the first item includes an item regarding efficiency of the
swing.
17. The swing diagnosis apparatus according to claim 16, wherein
the item regarding the efficiency is an item indicating a
relationship between a deceleration amount and a deceleration
period of a holding portion of an exercise appliance in the
downswing.
18. The swing diagnosis apparatus according to claim 13, wherein
the second item includes an item indicating a relationship between
an incidence angle of a ball hitting portion of an exercise
appliance and an inclination of the ball hitting portion at
impact.
19. The swing diagnosis apparatus according to claim 13, wherein
the second item includes an item regarding a speed of an exercise
appliance at impact.
20. The swing diagnosis apparatus according to claim 13, wherein
the plurality of items include a third item regarding a time at
which the backswing transitions to the downswing and a time of the
impact.
21. The swing diagnosis apparatus according to claim 20, wherein
the third item includes an item indicating a relationship between
(i) a rotation angle about a rotation axis of an exercise appliance
at the time at which the backswing transitions to the downswing, a
longitudinal direction of the exercise appliance being the rotation
axis, and (ii) an inclination of a ball hitting portion of the
exercise appliance at the time of the impact.
Description
BACKGROUND
1. Technical Field
The present invention relates to a swing diagnosis method, a
recording medium, a swing diagnosis apparatus, and a swing
diagnosis system.
2. Related Art
JP-A-2004-135908 discloses a measurement system provided with
sensor means for detecting passing of a golf club head which is
swung downward in order to hit a golf ball; an impact camera which
captures an image of impact; a first ball measurement camera and a
second ball measurement camera which are set at positions separated
from each other by a predetermined distance along a flight line
(flight trajectory) of a hit ball in order to capture images of the
hit ball after the impact; a performance measurement device of the
golf club; and a monitor which displays a movement state of the
golf ball. The measurement system analyzes a movement state of the
hit golf ball on the basis of the images, and displays the movement
state of the golf ball as a radar chart. Therefore, according to
the measurement system, it is possible to easily evaluate
performance of a golf club on the basis of a movement state of the
golf ball.
However, the measurement system disclosed in JP-A-2004-135908
displays a movement state of the hit golf ball, that is, data after
impact, as a radar chart, and thus it is hard to understand
features of a swing till the impact even if the radar chart is
observed.
SUMMARY
An advantage of some aspects of the invention is to provide a swing
diagnosis method, a recording medium, a swing diagnosis apparatus,
and a swing diagnosis system, capable of clearly showing features
of a swing till impact.
The invention can be implemented as the following forms or
application examples.
APPLICATION EXAMPLE 1
A swing diagnosis method according to this application example
includes a procedure of calculating levels of a plurality of items
including a first item regarding at least one of a backswing and a
downswing, and a second item regarding impact on the basis of data
regarding a swing; and a procedure of outputting information of the
levels of the plurality of items.
The data regarding the swing may be, for example, measured data of
acceleration or angular velocity regarding the swing, and may be
analysis information including values of indexes indicating
features of the swing, obtained by analyzing the measured data.
Alternatively, the data regarding the swing may be data in which
some or all values of indexes indicating features of the swing are
pseudo-values. The data regarding the swing may be data based on an
output signal from an inertial sensor measuring acceleration or
angular velocity regarding the swing.
According to the swing diagnosis method of this application
example, it is possible to grade and diagnose a feature of the
backswing or the downswing by calculating a level of the first item
regarding at least one of the backswing and the downswing on the
basis of the data regarding the swing. According to the swing
diagnosis method of the application example, it is also possible to
grade and diagnose a feature of the swing at impact by calculating
a level of the second item regarding the impact on the basis of the
data regarding the swing. According to the swing diagnosis method
of the application example, it is possible to grade and clearly
show features of the swing till the impact by outputting level
information of the plurality of items including the first item and
the second item.
APPLICATION EXAMPLE 2
In the swing diagnosis method according to the application example,
the first item may include an item indicating a relationship
between at least one virtual plane, and a position of a ball
hitting portion of an exercise appliance at a first timing during
the backswing and a position of the ball hitting portion at a
second timing during the downswing.
The first timing may be the time at which a long axis direction of
the exercise appliance becomes a direction along a horizontal
direction during the backswing. The second timing may be the time
at which the long axis direction of the exercise appliance becomes
a direction along the horizontal direction during the
downswing.
The exercise appliance is a tool used for a swing, and may be, for
example, a golf club, a tennis racket, a baseball bat, or a hockey
stick.
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on a relationship between the virtual plane and
positions of the ball hitting portion of the exercise appliance at
desired timings during the backswing and the downswing.
APPLICATION EXAMPLE 3
In the swing diagnosis method according to the application example,
the at least one virtual plane may include a first virtual plane
that is specified on the basis of a first axis along a target hit
ball direction, and a second axis along a longitudinal direction of
the exercise appliance before starting the backswing; and a second
virtual plane that forms a first angle with the first virtual
plane.
The target hit ball direction may be a direction in a reference
plane (for example, a horizontal plane).
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on relationships among the first virtual plane, the
second virtual plane, and positions of the ball hitting portion of
the exercise appliance at desired timings during the backswing and
the downswing.
APPLICATION EXAMPLE 4
In the swing diagnosis method according to the application example,
the first item may include an item regarding the efficiency of the
swing.
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on the efficiency of the swing.
APPLICATION EXAMPLE 5
In the swing diagnosis method according to the application example,
the item regarding the swing efficiency may be an item indicating a
relationship between a deceleration amount and a deceleration
period of a holding portion of the exercise appliance in the
downswing.
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on a deceleration amount and a deceleration period of
the holding portion of the exercise appliance in the downswing.
APPLICATION EXAMPLE 6
In the swing diagnosis method according to the application example,
the second item may include an item indicating a relationship
between an incidence angle of a ball hitting portion of an exercise
appliance and an inclination of the ball hitting portion at
impact.
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on a relationship between an incidence angle of the
ball hitting portion of the exercise appliance and an inclination
of the ball hitting portion at impact.
APPLICATION EXAMPLE 7
In the swing diagnosis method according to the application example,
the second item may include an item regarding a speed of an
exercise appliance at impact.
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on a speed of the exercise appliance at impact.
APPLICATION EXAMPLE 8
In the swing diagnosis method according to the application example,
the plurality of items may further include a third item regarding
the time at which the backswing transitions to the downswing and
the impact.
According to the swing diagnosis method of this application
example, it is also possible to grade and diagnose a feature of the
swing in which the time of starting the downswing and the time of
finishing the downswing are taken into particular consideration by
calculating a level of the third item regarding the time at which
the backswing transitions to the downswing, and the impact on the
basis of the data regarding the swing. According to the swing
diagnosis method of the application example, it is possible to
grade and clearly show features of the swing till the impact by
outputting level information of a plurality of items including the
first item, the second item, and the third item.
APPLICATION EXAMPLE 9
In the swing diagnosis method according to the application example,
the third item may include an item indicating a relationship
between a rotation angle about a rotation axis of an exercise
appliance at a timing at which the backswing transitions to the
downswing with a longitudinal direction of the exercise appliance
as the rotation axis, and an inclination of a ball hitting portion
of the exercise appliance at a timing of the impact.
According to the swing diagnosis method of this application
example, it is possible to grade and clearly show a feature of the
swing based on a relationship between a rotation angle about a
longitudinal direction of the exercise appliance at the time of
starting the downswing and an inclination of the ball hitting
portion of the exercise appliance at impact.
APPLICATION EXAMPLE 10
In the swing diagnosis method according to the application example,
the levels may be scores.
According to the swing diagnosis method of this application
example, it is possible to digitalize and clearly show a feature of
the swing till the impact.
APPLICATION EXAMPLE 11
A swing diagnosis program according to this application example
causes a computer to execute a procedure of calculating levels of a
plurality of items including a first item regarding at least one of
a backswing and a downswing, and a second item regarding impact on
the basis of data regarding a swing; and a procedure of outputting
information of the levels of the plurality of items.
APPLICATION EXAMPLE 12
A recording medium according to this application example records a
swing diagnosis program causing a computer to execute a procedure
of calculating levels of a plurality of items including a first
item regarding at least one of a backswing and a downswing, and a
second item regarding impact on the basis of data regarding a
swing; and a procedure of outputting information of the levels of
the plurality of items.
APPLICATION EXAMPLE 13
A swing diagnosis apparatus according to this application example
includes a level calculation section that calculates levels of a
plurality of items including a first item regarding at least one of
a backswing and a downswing, and a second item regarding impact on
the basis of data regarding a swing; and an output section that
outputs information of the levels of the plurality of items.
According to the swing diagnosis program, the recording medium, or
the swing diagnosis apparatus of these application examples, it is
possible to grade and diagnose a feature of the backswing or the
downswing by calculating a level of the first item regarding at
least one of the backswing and the downswing on the basis of the
data regarding the swing. According to the application example, it
is also possible to grade and diagnose a feature of the swing at
impact by calculating a level of the second item regarding the
impact on the basis of the data regarding the swing. According to
the application example, it is possible to grade and clearly show
features of the swing till the impact by outputting level
information of the plurality of items including the first item and
the second item.
APPLICATION EXAMPLE 14
A swing diagnosis system according to this application example
includes any one of the swing diagnosis apparatuses according to
the application examples; and an inertial sensor that measures the
swing.
The inertial sensor may be a sensor which can measure an inertial
amount such as acceleration or angular velocity, and may be, for
example, an inertial measurement unit (IMU) which can measure
acceleration or angular velocity. For example, the inertial sensor
may be attached to an exercise appliance or a part of a user so as
to be attachable to and detachable from the exercise appliance or
the user, and may be fixed to the exercise appliance so as to not
be detached therefrom as a result of being built into the exercise
appliance.
According to the swing diagnosis system of this application
example, the swing diagnosis apparatus can level and diagnose a
feature of the backswing or the downswing by calculating a level of
the first item regarding at least one of the backswing and the
downswing on the basis of the data regarding the swing, obtained
through measurement in the inertial sensor. According to the swing
diagnosis system of the application example, the swing diagnosis
apparatus can also level and diagnose a feature of the swing at
impact by calculating a level of the second item regarding the
impact on the basis of the data regarding the swing, obtained
through measurement in the inertial sensor. According to the swing
diagnosis system of the application example, the swing diagnosis
apparatus can level and clearly show features of the swing till the
impact by outputting level information of the plurality of items
including the first item and the second item.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying
drawings, wherein like numbers reference like elements.
FIG. 1 is a diagram illustrating a configuration example of a swing
diagnosis system of an embodiment.
FIG. 2 is a diagram illustrating an example in which a sensor unit
is attached.
FIG. 3 is a diagram illustrating examples of a position at which
and a direction in which the sensor unit is attached.
FIG. 4 is a diagram illustrating procedures of actions performed by
a user until the user hits a ball.
FIG. 5 is a diagram illustrating an example of an input screen of
physical information and golf club information.
FIG. 6 is a diagram illustrating a swing action.
FIG. 7 is a diagram illustrating an example of a selection screen
of swing analysis data.
FIG. 8 is a diagram illustrating an example of an editing screen of
input data which is a swing diagnosis target.
FIG. 9 is a diagram illustrating an example of a swing diagnosis
screen.
FIG. 10 is a diagram illustrating configuration examples of the
sensor unit and a swing analysis apparatus.
FIG. 11 is a plan view in which a golf club and the sensor unit are
viewed from a negative side of an X axis during standing still of
the user.
FIG. 12 is a graph illustrating examples of temporal changes of
three-axis angular velocities.
FIG. 13 is a graph illustrating a temporal change of a combined
value of the three-axis angular velocities.
FIG. 14 is a graph illustrating a temporal change of a derivative
of the combined value.
FIG. 15 is a diagram illustrating a shaft plane and a Hogan
plane.
FIG. 16 is a view in which a sectional view of the shaft plane
which is cut in a YZ plane is viewed from the negative side of the
X axis.
FIG. 17 is a view in which a sectional view of the Hogan plane
which is cut in the YZ plane is viewed from the negative side of
the X axis.
FIG. 18 is a diagram for explaining a face angle and a club path
(incidence angle).
FIG. 19 is a diagram illustrating an example of a temporal change
of a shaft axis rotation angle from swing starting (backswing
starting) to impact.
FIG. 20 is a diagram illustrating an example of a temporal change
of a speed of a grip in a downswing.
FIG. 21 is a flowchart illustrating examples of procedures of a
swing analysis process (swing analysis method).
FIG. 22 is a diagram illustrating a configuration example of a
swing diagnosis apparatus.
FIG. 23 is a diagram illustrating examples of relationships among
the shaft plane and the Hogan plane, and a plurality of
regions.
FIG. 24 is a diagram illustrating an example of a V zone score
table.
FIG. 25 is a diagram illustrating an example of a rotation score
table.
FIG. 26 is a diagram illustrating an example of an impact score
table.
FIG. 27 is a diagram illustrating an example of a speed score
table.
FIG. 28 is a diagram illustrating an example of a swing efficiency
score table.
FIG. 29 is a flowchart illustrating examples of procedures of a
process performed by the swing analysis apparatus in relation to a
swing diagnosis process.
FIG. 30 is a flowchart illustrating examples of procedures of the
swing diagnosis process (swing diagnosis method).
FIG. 31 is a flowchart illustrating examples of procedures of a
process of calculating scores and a total score of a plurality of
items.
FIG. 32 is a diagram illustrating a configuration example of a
swing diagnosis system according to a modification example.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Hereinafter, preferred embodiments of the invention will be
described with reference to the drawings. The embodiments described
below are not intended to improperly limit the content of the
invention disclosed in the appended claims. In addition, all
constituent elements described below are not essential constituent
elements of the invention.
Hereinafter, a swing diagnosis system performing diagnosis of a
golf swing will be described as an example.
1. Swing Diagnosis System
1-1. Summary of Swing Diagnosis System
FIG. 1 is a diagram illustrating a configuration example of a swing
diagnosis system of the present embodiment. As illustrated in FIG.
1, a swing diagnosis system 1 of the present embodiment is
configured to include a sensor unit 10, a swing analysis apparatus
20, and a swing diagnosis apparatus 30.
The sensor unit 10 (an example of an inertial sensor measuring a
swing) can measure acceleration generated in each axial direction
of three axes and angular velocity generated around each of the
three axes, and is attached to a golf club 3 as illustrated in FIG.
2.
In the present embodiment, as illustrated in FIG. 3, the sensor
unit 10 is attached to a part of a shaft so that one axis of three
detection axes (an x axis, a y axis, and a z axis), for example,
the y axis matches a longitudinal direction of the shaft of the
golf club 3 (a longitudinal direction of the golf club 3).
Preferably, the sensor unit 10 is attached to a position close to a
grip to which impact during ball hitting is hardly forwarded and
centrifugal force is hardly applied during swing. The shaft is a
shaft portion other than a head of the golf club 3 and also
includes the grip. However, the sensor unit 10 may be attached to a
part (for example, the hand or a glove) of a user 2, and may be
attached to an accessory such as a wristwatch.
The user 2 performs a swing action for hitting a golf ball 4
according to predefined procedures. FIG. 4 is a diagram
illustrating procedures of actions performed by the user 2 until
the user hits the ball in the present embodiment. As illustrated in
FIG. 4, first, the user 2 performs an input operation of physical
information of the user 2, information (golf club information)
regarding the golf club 3 used by the user 2, and the like via the
swing analysis apparatus 20 (step S1). The physical information
includes at least one of information regarding a height, a length
of the arms, and a length of the legs of the user 2, and may
further include information regarding sex or other information. The
golf club information includes at least one of information
regarding a length (club length) of the golf club 3 and the type
(number) of golf club 3. Next, the user 2 performs a measurement
starting operation (an operation for starting measurement in the
sensor unit 10) via the swing analysis apparatus 20 (step S2).
Next, after receiving a notification (for example, a notification
using a voice) of giving an instruction for taking an address
attitude (a basic attitude before starting a swing) from the swing
analysis apparatus 20 (Y in step S3), the user 2 takes an address
attitude so that the axis in the longitudinal direction of the
shaft of the golf club 3 is perpendicular to a target line (target
hit ball direction), and stands still (step S4). Next, the user 2
receives a notification (for example, a notification using a voice)
of permitting a swing from the swing analysis apparatus 20 (Y in
step S5), and then hits the golf ball 4 by performing a swing
action (step S6).
FIG. 5 is a diagram illustrating an example of an input screen of
physical information and golf club information, displayed on a
display section 25 (refer to FIG. 10) of the swing analysis
apparatus 20. In step S1 in FIG. 4, the user 2 inputs physical
information such as a height, sex, age, and country, and inputs
golf club information such as a club length (a length of the
shaft), and a club number on the input screen illustrated in FIG.
5. Information included in the physical information is not limited
thereto, and, the physical information may include, for example, at
least one of information regarding a length of the arms and a
length of the legs instead of or along with the height. Similarly,
information included in the golf club information is not limited
thereto, and, for example, the golf club information may not
include at least one of information regarding the club length and
the number, and may include other information.
If the user 2 performs the measurement starting operation in step
S2 in FIG. 4, the swing analysis apparatus 20 transmits a
measurement starting command to the sensor unit 10, and the sensor
unit 10 receives the measurement starting command and starts
measurement of three-axis accelerations and three-axis angular
velocities. The sensor unit 10 measures three-axis accelerations
and three-axis angular velocities in a predetermined cycle (for
example, 1 ms), and sequentially transmits the measured data to the
swing analysis apparatus 20. Communication between the sensor unit
10 and the swing analysis apparatus 20 may be wireless
communication, and may be wired communication.
The swing analysis apparatus 20 notifies the user 2 of permission
of swing starting, shown in step S5 in FIG. 4, and then analyzes
the swing action (step S6 in FIG. 4) in which the user 2 has hit
the ball by using the golf club 3 on the basis of measured data
from the sensor unit 10.
As illustrated in FIG. 6, the swing action performed by the user 2
in step S6 in FIG. 4 includes an action reaching impact (ball
hitting) at which the golf ball 4 is hit through respective states
of halfway back at which the shaft of the golf club 3 becomes
horizontal during the backswing after starting a swing (backswing),
a top at which the swing changes from the backswing to a downswing,
and halfway down at which the shaft of the golf club 3 becomes
horizontal during the downswing. The swing analysis apparatus 20
generates swing analysis data including information regarding a
time point (date and time) at which the swing is performed,
identification information or the sex of the user 2, the type of
golf club 3, and an analysis result of the swing action, and
transmits the swing analysis data to the swing diagnosis apparatus
30 via a network 40 (refer to FIG. 1).
The swing diagnosis apparatus 30 receives the swing analysis data
transmitted by the swing analysis apparatus 20 via the network 40,
and preserves the swing analysis data. Therefore, when the user 2
performs a swing action according to the procedures illustrated in
FIG. 4, the swing analysis data generated by the swing analysis
apparatus 20 is preserved in the swing diagnosis apparatus 30, and
thus a swing analysis data list is built.
For example, the swing analysis apparatus 20 is implemented by an
information terminal (client terminal) such as a smart phone or a
personal computer, and the swing diagnosis apparatus 30 is
implemented by a server which processes requests from the swing
analysis apparatus 20.
The network 40 may be a wide area network (WAN) such as the
Internet, and may be a local area network (LAN). The swing analysis
apparatus 20 and the swing diagnosis apparatus 30 may communicate
with each other through, for example, near field communication or
wired communication, without using the network 40.
In the present embodiment, if the user 2 activates a swing
diagnosis application via an operation section 23 (refer to FIG.
10) of the swing analysis apparatus 20, the swing analysis
apparatus 20 performs communication with the swing diagnosis
apparatus 30, and, for example, a selection screen of swing
analysis data as illustrated in FIG. 7 is displayed on the display
section 25 of the swing analysis apparatus 20. The selection screen
includes a time point (date and time), the type of golf club which
has been used, and some index values as analysis results of a
swing, with respect to each item of swing analysis data regarding
the user 2 included in the swing analysis data list preserved in
the swing diagnosis apparatus 30.
A checkbox correlated with each item of swing analysis data is
located at a left end of the selection screen illustrated in FIG.
7, and the user 2 checks any one of the checkboxes by operating the
swing analysis apparatus 20, and then presses an OK button located
on a lower part of the selection screen. Consequently, the swing
analysis apparatus 20 performs communication with the swing
diagnosis apparatus 30, for example, an editing screen of input
data which is a swing diagnosis target, as illustrated in FIG. 8,
is displayed on the display section 25 of the swing analysis
apparatus 20, with respect to the swing analysis data correlated
with the checked checkbox on the selection screen illustrated in
FIG. 7.
The input data editing screen illustrated in FIG. 8 includes values
obtained on the basis of the selected swing analysis data as
initial values with respect to sex, the type of golf club (either
of a driver or an iron), and each index of a swing. Meanings or
calculation methods of the respective indexes (a region in which a
head position at halfway back is included, a region in which a head
position at halfway down is included, a face angle, a club path
(incidence angle), a shaft axis rotation angle at top, a head
speed, a grip deceleration ratio, and a grip deceleration time
ratio) included in the input data editing screen illustrated in
FIG. 8 will be described later.
The input data formed of the sex, the type of golf club, and the
respective index values in the input data editing screen
illustrated in FIG. 8 can be edited. The user 2 does not edit the
input data or edits the input data via the operation section 23
(refer to FIG. 10) of the swing analysis apparatus 20, and then
presses a diagnosis starting button located on a lower part of the
input data editing screen. Consequently, the swing analysis
apparatus 20 transmits the input data at the time of the diagnosis
starting button being pressed to the swing diagnosis apparatus
30.
The swing diagnosis apparatus 30 receives the input data, and
performs calculation of levels of a plurality of items by using the
input data. For example, the swing diagnosis apparatus 30 may
calculate a level of each of five items such as a "V zone",
"rotation", "impact", a "speed", and "swing efficiency", as 5
points maximum. Meanings or calculation methods of the five items
will be described later. The swing diagnosis apparatus 30 may
calculate a total score of a swing by using the respective levels
of the five items. The swing diagnosis apparatus 30 transmits
information regarding the calculated levels and total score of the
plurality of items to the swing analysis apparatus 20. The "levels"
may be represented by, for example, "1, 2, 3, . . . ", "A, B, C, .
. . ", "O, X, .DELTA., . . . ", and may be represented by
scores.
The swing analysis apparatus 20 receives the information regarding
levels and total score of the plurality of items, and displays, for
example, a swing diagnosis screen as illustrated in FIG. 9 on the
display section 25. The swing diagnosis screen illustrated in FIG.
9 includes input data information on a left part thereof. The input
data information is input data at the time of the diagnosis
starting button being pressed in the input data editing screen
illustrated in FIG. 8, that is, data information used for diagnosis
of the swing (that is, calculation of the levels and the total
score of the five items) in the swing diagnosis apparatus 30. The
swing diagnosis screen illustrated in FIG. 9 includes a radar chart
indicating scores as the levels of the five items on the central
part thereof, and includes information regarding the total score on
a right part thereof.
The user 2 can understand levels and a total score of the plurality
of items as diagnosis results for the input data on the left part
on the basis of the swing diagnosis screen illustrated in FIG. 9.
Particularly, if the user 2 presses the diagnosis starting button
without editing the input data on the input data editing screen
illustrated in FIG. 8, the user can understand a strong point or a
weak point in the user's swing on the basis of the swing diagnosis
screen illustrated in FIG. 9. On the other hand, if the user 2
edits the input data and presses the diagnosis starting button on
the input data editing screen illustrated in FIG. 8, the user can
understand which index is improved to what extent in order to
overcome the weak point. Hereinafter, a description will be made of
an example in which "levels" of a plurality of items are
represented by "scores", but, needless to say, the example can be
easily replaced with an example of the levels being expressed by
"1, 2, 3, . . . ", "A, B, C, . . . ", "O, X, .DELTA.", or the
like.
1-2. Configuration of Sensor Unit and Swing Analysis Apparatus
FIG. 10 is a diagram illustrating configuration examples of the
sensor unit 10 and the swing analysis apparatus 20. As illustrated
in FIG. 10, in the present embodiment, the sensor unit 10 is
configured to include an acceleration sensor 12, an angular
velocity sensor 14, a signal processing section 16, and a
communication section 18. However, the sensor unit 10 may have a
configuration in which some of the constituent elements are deleted
or changed as appropriate, or may have a configuration in which
other constituent elements are added thereto.
The acceleration sensor 12 measures respective accelerations in
three axial directions which intersect (ideally, orthogonal to)
each other, and outputs digital signals (acceleration data)
corresponding to magnitudes and directions of the measured
three-axis accelerations.
The angular velocity sensor 14 measures respective angular
velocities in three axial directions which intersect (ideally,
orthogonal to) each other, and outputs digital signals (angular
velocity data) corresponding to magnitudes and directions of the
measured three-axis angular velocities.
The signal processing section 16 receives the acceleration data and
the angular velocity data from the acceleration sensor 12 and the
angular velocity sensor 14, respectively, adds time information
thereto, stores the data in a storage portion (not illustrated),
adds time information to the stored measured data (acceleration
data and angular velocity data) so as to generate packet data
conforming to a communication format, and outputs the packet data
to the communication section 18.
Ideally, the acceleration sensor 12 and the angular velocity sensor
14 are provided in the sensor unit 10 so that the three axes
thereof match three axes (an x axis, a y axis, and a z axis) of an
orthogonal coordinate system (sensor coordinate system) defined for
the sensor unit 10, but, actually, errors occur in installation
angles. Therefore, the signal processing section 16 performs a
process of converting the acceleration data and the angular
velocity data into data in the xyz coordinate system by using a
correction parameter which is calculated in advance according to
the installation angle errors.
The signal processing section 16 may perform a process of
correcting the temperatures of the acceleration sensor 12 and the
angular velocity sensor 14. The acceleration sensor 12 and the
angular velocity sensor 14 may have a temperature correction
function.
The acceleration sensor 12 and the angular velocity sensor 14 may
output analog signals, and, in this case, the signal processing
section 16 may A/D convert an output signal from the acceleration
sensor 12 and an output signal from the angular velocity sensor 14
so as to generate measured data (acceleration data and angular
velocity data), and may generate communication packet data by using
the data.
The communication section 18 performs a process of transmitting
packet data received from the signal processing section 16 to the
swing analysis apparatus 20, or a process of receiving various
control commands such as a measurement starting command from the
swing analysis apparatus 20 and sending the control command to the
signal processing section 16. The signal processing section 16
performs various processes corresponding to control commands.
As illustrated in FIG. 10, in the present embodiment, the swing
analysis apparatus 20 is configured to include a processing section
21, a communication section 22, an operation section 23, a storage
section 24, a display section 25, a sound output section 26, and a
communication section 27. However, the swing analysis apparatus 20
may have a configuration in which some of the constituent elements
are deleted or changed as appropriate, or may have a configuration
in which other constituent elements are added thereto.
The communication section 22 performs a process of receiving packet
data transmitted from the sensor unit 10 and sending the packet
data to the processing section 21, or a process of transmitting a
control command from the processing section 21 to the sensor unit
10.
The operation section 23 performs a process of acquiring operation
data from the user 2 and sending the operation data to the
processing section 21. The operation section 23 may be, for
example, a touch panel type display, a button, a key, or a
microphone.
The storage section 24 is constituted of, for example, various IC
memories such as a read only memory (ROM), a flash ROM, and a
random access memory (RAM), or a recording medium such as a hard
disk or a memory card. The storage section 24 stores a program for
the processing section 21 performing various calculation processes
or a control process, or various programs or data for realizing
application functions.
In the present embodiment, the storage section 24 stores a swing
analysis program 240 which is read by the processing section 21 and
executes a swing analysis process. The swing analysis program 240
may be stored in a nonvolatile recording medium (computer readable
recording medium) in advance, or the swing analysis program 240 may
be received from a server (not illustrated) or the swing diagnosis
apparatus 30 by the processing section 21 via a network, and may be
stored in the storage section 24.
In the present embodiment, the storage section 24 stores golf club
information 242, physical information 244, sensor attachment
position information 246, and swing analysis data 248. For example,
the user 2 may operate the operation section 23 so as to input
specification information regarding the golf club 3 to be used (for
example, at least some information such as information regarding a
length of the shaft, a position of the centroid thereof, a lie
angle, a face angle, a loft angle, and the like) from the input
screen illustrated in FIG. 5, and the input specification
information may be used as the golf club information 242.
Alternatively, in step S1 in FIG. 4, the user 2 may sequentially
input type numbers of the golf club 3 (alternatively, selects a
type number from a type number list) so that specification
information for each type number is stored in the storage section
24 in advance. In this case, specification information of an input
type number may be used as the golf club information 242.
For example, the user 2 may input physical information by operating
the operation section 23 from the input screen illustrated in FIG.
5, and the input physical information may be used as the physical
information 244. For example, in step S1 in FIG. 4, the user 2 may
input an attachment position of the sensor unit 10 and a distance
to the grip end of the golf club 3 by operating the operation
section 23, and the input distance information may be used as the
sensor attachment position information 246. Alternatively, the
sensor unit 10 may be attached at a defined predetermined position
(for example, a distance of 20 cm from the grip end), and thus
information regarding the predetermined position may be stored as
the sensor attachment position information 246 in advance.
The swing analysis data 248 is data including information regarding
a swing action analysis result in the processing section 21 (swing
analysis portion 211) along with a time point (date and time) at
which a swing was performed, identification information or the sex
of the user 2, and the type of golf club 3.
The storage section 24 is used as a work area of the processing
section 21, and temporarily stores data which is input from the
operation section 23, results of calculation executed by the
processing section 21 according to various programs, and the like.
The storage section 24 may store data which is required to be
preserved for a long period of time among data items generated
through processing of the processing section 21.
The display section 25 displays a processing result in the
processing section 21 as text, a graph, a table, animation, and
other images. The display section 25 may be, for example, a CRT, an
LCD, a touch panel type display, and a head mounted display (HMD).
A single touch panel type display may realize functions of the
operation section 23 and the display section 25.
The sound output section 26 outputs a processing result in the
processing section 21 as a sound such as a voice or a buzzer sound.
The sound output section 26 may be, for example, a speaker or a
buzzer.
The communication section 27 performs data communication with a
communication section 32 (refer to FIG. 22) of the swing diagnosis
apparatus 30 via the network 40. For example, the communication
section 27 performs a process of receiving the swing analysis data
248 from the processing section 21 after a swing analysis process
is completed, and transmitting the swing analysis data to the
communication section 32 of the swing diagnosis apparatus 30. For
example, the communication section 27 performs a process of
receiving information required to display the selection screen
illustrated in FIG. 7 from the communication section 32 of the
swing diagnosis apparatus 30 and transmitting the information to
the processing section 21, and a process of receiving selected
information on the selection screen illustrated in FIG. 7 from the
processing section 21 and transmitting the selected information to
the communication section 32 of the swing diagnosis apparatus 30.
For example, the communication section 27 performs a process of
receiving information required to display the input data editing
screen illustrated in FIG. 8 from the communication section 32 of
the swing diagnosis apparatus 30, and transmitting the information
to the processing section 21. For example, the communication
section 27 performs a process of receiving input data at the time
of the diagnosis starting button on the input data editing screen
illustrated in FIG. 8 being pressed from the processing section 21,
and transmitting the input data to the communication section 32 of
the swing diagnosis apparatus 30. For example, the communication
section 27 performs a process of receiving information (diagnosis
result information (scores or a total score of a plurality of
items) based on the input data) required to display the swing
diagnosis screen illustrated in FIG. 9 from the communication
section 32 of the swing diagnosis apparatus 30, and transmitting
the information to the processing section 21.
The processing section 21 performs a process of transmitting a
control command to the sensor unit 10 via the communication section
22, or various computation processes on data which is received from
the sensor unit 10 via the communication section 22, according to
various programs. The processing section 21 performs a process of
reading the swing analysis data 248 from the storage section 24,
and transmitting the swing analysis data to the swing diagnosis
apparatus 30 via the communication section 27, according to various
programs. The processing section 21 performs a process of
transmitting various pieces of information to the swing diagnosis
apparatus 30 via the communication section 27, and displaying
various screens (the respective screens illustrated in FIGS. 7, 8
and 9) on the basis of the information received from the swing
diagnosis apparatus 30, according to various programs. The
processing section 21 performs other various control processes.
Particularly, in the present embodiment, by executing the swing
analysis program 240, the processing section 21 functions as a data
acquisition portion 210, a swing analysis portion 211, an image
data generation portion 212, a storage processing portion 213, a
display processing portion 214, and a sound output processing
portion 215, and performs a process (swing analysis process) of
analyzing a swing action of the user 2.
The data acquisition portion 210 performs a process of receiving
packet data which is received from the sensor unit 10 by the
communication section 22, acquiring time information and measured
data in the sensor unit 10 from the received packet data, and
sending the time information and the measured data to the storage
processing portion 213. The data acquisition portion 210 performs a
process of receiving the information required to display the
various screens (the respective screens illustrated in FIGS. 7, 8
and 9), received from the swing diagnosis apparatus 30 by the
communication section 27, and transmitting the information to the
image data generation portion 212.
The storage processing portion 213 performs read/write processes of
various programs or various data for the storage section 24. The
storage processing portion 213 performs not only the process of
storing the time information and the measured data received from
the data acquisition portion 210 in the storage section 24 in
correlation with each other, but also a process of storing various
pieces of information calculated by the swing analysis portion 211,
the swing analysis data 248, or the like in the storage section
24.
The swing analysis portion 211 performs a process of analyzing a
swing action of the user 2 by using the measured data (the measured
data stored in the storage section 24) output from the sensor unit
10, the data from the operation section 23, or the like, so as to
generate the swing analysis data 248 including a time point (date
and time) at which the swing was performed, identification
information or the sex of the user 2, the type of golf club 3, and
information regarding a swing action analysis result. Particularly,
in the present embodiment, the swing analysis portion 211
calculates a value of each index of the swing as at least some of
the information regarding the swing action analysis result.
The swing analysis portion 211 may calculate at least one virtual
plane as an index of the swing. For example, at least one virtual
plane includes a shaft plane SP (first virtual plane) which will be
described later, and a Hogan plane HP (second virtual plane) which
will be described later forming a first angle with the shaft plane
SP, and the swing analysis portion 211 may calculate the "shaft
plane SP" and the "Hogan plane HP" as the indexes.
The swing analysis portion 211 may calculate a position of the head
of the golf club 3 at a first timing during the backswing as an
index of the swing. For example, the first timing is the time of
halfway back at which the longitudinal direction of the golf club 3
becomes a direction along the horizontal direction during the
backswing, and the swing analysis portion 211 may calculate a
"position of the head at halfway back" which will be described
later as the index.
The swing analysis portion 211 may calculate a position of the head
of the golf club 3 at a second timing during the downswing as an
index of the swing. For example, the second timing is the time of
halfway down at which the longitudinal direction of the golf club 3
becomes a direction along the horizontal direction during the
downswing, and the swing analysis portion 211 may calculate a
"position of the head at halfway down" which will be described
later as the index.
The swing analysis portion 211 may calculate an index based on an
incidence angle of the head of the golf club 3 at impact (at ball
hitting), as an index of the swing. For example, the swing analysis
portion 211 may calculate a "club path (incidence angle) .psi."
which will be described later as the index.
The swing analysis portion 211 may calculate an index based on an
inclination of the head of the golf club 3 at impact (at ball
hitting) as an index of the swing. For example, the swing analysis
portion 211 may calculate an "(absolute) face angle .PHI." or a
"relative face angle .eta." which will be described later as the
index.
The swing analysis portion 211 may calculate an index based on a
speed of the head of the golf club 3 at impact (at ball hitting) as
an index of the swing. For example, the swing analysis portion 211
may calculate a "head speed" which will be described later as the
index.
The swing analysis portion 211 may calculate an index based on a
rotation angle about a rotation axis (hereinafter, referred to as
about the long axis) of the shaft of the golf club 3 at a
predetermined timing between the time of starting a backswing and
the time of impact (at ball hitting) with the longitudinal
direction of the shaft as the rotation axis, as an index of the
swing. The rotation angle about the long axis of the golf club 3
may be an angle by which the golf club 3 is rotated about the long
axis from a reference timing to a predetermined timing. The
reference timing may be the time of starting a backswing, and may
be the time of address. The predetermined timing may be the time
(the time of a top) at which a backswing transitions to a
downswing. For example, the swing analysis portion 211 may
calculate a "shaft axis rotation angle .theta..sub.top at top"
which will be described later as the index.
The swing analysis portion 211 may calculate an index based on a
deceleration amount of the grip of the golf club 3 during the
downswing as an index of the swing. For example, the swing analysis
portion 211 may calculate a "grip deceleration ratio R.sub.V" which
will be described later as the index.
The swing analysis portion 211 may calculate an index based on a
deceleration period of the grip of the golf club 3 during the
downswing as an index of the swing. For example, the swing analysis
portion 211 may calculate a "grip deceleration time ratio R.sub.T"
which will be described later as the index.
However, the swing analysis portion 211 may not calculate values of
some of the indexes, and may calculate values of other indexes, as
appropriate.
The image data generation portion 212 performs a process of
generating image data corresponding to an image displayed on the
display section 25. For example, the image data generation portion
212 generates image data corresponding to the selection screen
illustrated in FIG. 7, the input data editing screen illustrated in
FIG. 8, and the swing diagnosis screen illustrated in FIG. 9 on the
basis of various pieces of information received by the data
acquisition portion 210.
The display processing portion 214 performs a process of displaying
various images (including text, symbols, and the like in addition
to an image corresponding to the image data generated by the image
data generation portion 212) on the display section 25. For
example, the display processing portion 214 displays the selection
screen illustrated in FIG. 7, the input data editing screen
illustrated in FIG. 8, the swing diagnosis screen illustrated in
FIG. 9, and the like, on the display section 25, on the basis of
the image data generated by the image data generation portion 212.
For example, the image data generation portion 212 may display an
image, text, or the like for notifying the user 2 of permission of
swing starting on the display section 25 in step S5 in FIG. 4. For
example, the display processing portion 214 may display text
information such as text or symbols indicating an analysis result
in the swing analysis portion 211 on the display section 25
automatically or in response to an input operation performed by the
user 2 after a swing action of the user 2 is completed.
Alternatively, a display section may be provided in the sensor unit
10, and the display processing portion 214 may transmit image data
to the sensor unit 10 via the communication section 22, and various
images, text, or the like may be displayed on the display section
of the sensor unit 10.
The sound output processing portion 215 performs a process of
outputting various sounds (including voices, buzzer sounds, and the
like) from the sound output section 26. For example, the sound
output processing portion 215 may output a sound for notifying the
user 2 of permission of swing starting from the sound output
section 26 in step S5 in FIG. 4. For example, the sound output
processing portion 215 may output a sound or a voice indicating an
analysis result in the swing analysis portion 211 from the sound
output section 26 automatically or in response to an input
operation performed by the user 2 after a swing action of the user
2 is completed. Alternatively, a sound output section may be
provided in the sensor unit 10, and the sound output processing
portion 215 may transmit various items of sound data or voice data
to the sensor unit 10 via the communication section 22, and may
output various sounds or voices from the sound output section of
the sensor unit 10.
A vibration mechanism may be provided in the swing analysis
apparatus 20 or the sensor unit 10, and various pieces of
information may be converted into vibration information by the
vibration mechanism so as to be presented to the user 2.
1-3. Swing Analysis Process
In the present embodiment, when a position of the head of the golf
club 3 at address (during standing still) is set to the origin, an
XYZ coordinate system (global coordinate system) is defined which
has a target line indicating a target hit ball direction as an X
axis, an axis on a horizontal plane which is perpendicular to the X
axis as a Y axis, and a vertically upward direction (a direction
opposite to the gravitational direction) as a Z axis. In order to
calculate each index value, the swing analysis portion 211
calculates a position and an attitude of the sensor unit 10 in a
time series from the time of the address in the XYZ coordinate
system (global coordinate system) by using measured data
(acceleration data and angular velocity data) in the sensor unit
10. The swing analysis portion 211 detects respective timings of
the swing starting, the top, and the impact illustrated in FIG. 6,
by using the measured data (acceleration data or angular velocity
data) in the sensor unit 10. The swing analysis portion 211
calculates values of the respective indexes (for example, a shaft
plane, a Hogan plane, a head position at halfway back, a head
position at halfway down, a face angle, a club path (incidence
angle), a shaft axis rotation angle at top, a head speed, a grip
deceleration ratio, and a grip deceleration time ratio) of the
swing by using the time series data of the position and the
attitude of the sensor unit 10, and the timings of the swing
starting, the top, and the impact, so as to generate the swing
analysis data 248.
Calculation of Position and Attitude of Sensor Unit 10
If the user 2 performs the action in step S4 in FIG. 4, first, the
swing analysis portion 211 determines that the user 2 stands still
at an address attitude in a case where an amount of changes in
acceleration data measured by the acceleration sensor 12 does not
continuously exceed a threshold value for a predetermined period of
time. Next, the swing analysis portion 211 computes an offset
amount included in the measured data by using the measured data
(acceleration data and angular velocity data) for the predetermined
period of time. Next, the swing analysis portion 211 subtracts the
offset amount from the measured data so as to perform bias
correction, and computes a position and an attitude of the sensor
unit 10 during a swing action of the user 2 (during the action in
step S6 in FIG. 4) by using the bias-corrected measured data.
Specifically, first, the swing analysis portion 211 computes a
position (initial position) of the sensor unit 10 during standing
still (at address) of the user 2 in the XYZ coordinate system
(global coordinate system) by using the acceleration data measured
by the acceleration sensor 12, the golf club information 242, and
the sensor attachment position information 246.
FIG. 11 is a plan view in which the golf club 3 and the sensor unit
10 during standing still (at address) of the user 2 are viewed from
a negative side of the X axis. The origin O (0,0,0) is set at a
position 61 of the head of the golf club 3, and coordinates of a
position 62 of a grip end are (0, G.sub.Y, G.sub.Z). Since the user
2 performs the action in step S4 in FIG. 4, the position 62 of the
grip end or the initial position of the sensor unit 10 has an X
coordinate of 0, and is present on a YZ plane. As illustrated in
FIG. 11, the gravitational acceleration of 1 G is applied to the
sensor unit 10 during standing still of the user 2, and thus a
relationship between a y axis acceleration y (0) measured by the
sensor unit 10 and an inclined angle (an angle formed between the
long axis of the shaft and the horizontal plane (XY plane)) .alpha.
of the shaft of the golf club 3 is expressed by Equation (1).
y(0)=1Gsin .alpha. (1)
Therefore, the swing analysis portion 211 can calculate the
inclined angle .alpha. according to Equation (1) by using any
acceleration data between any time points at address (during
standing still).
Next, the swing analysis portion 211 subtracts a distance L.sub.SG
between the sensor unit 10 and the grip end included in the sensor
attachment position information 246 from a length L.sub.1 of the
shaft included in the golf club information 242, so as to obtain a
distance L.sub.SH between the sensor unit 10 and the head. The
swing analysis portion 211 sets, as the initial position of the
sensor unit 10, a position separated by the distance L.sub.SH from
the position 61 (origin O) of the head in a direction (a negative
direction of the y axis of the sensor unit 10) specified by the
inclined angle .alpha. of the shaft.
The swing analysis portion 211 integrates subsequent acceleration
data so as to compute coordinates of a position from the initial
position of the sensor unit 10 in a time series.
The swing analysis portion 211 computes an attitude (initial
attitude) of the sensor unit 10 during standing still (at address)
of the user 2 in the XYZ coordinate system (global coordinate
system) by using acceleration data measured by the acceleration
sensor 12. Since the user 2 performs the action in step S4 in FIG.
4, the x axis of the sensor unit 10 matches the X axis of the XYZ
coordinate system in terms of direction at address (during standing
still) of the user 2, and the y axis of the sensor unit 10 is
present on the YZ plane. Therefore, the swing analysis portion 211
can specify the initial attitude of the sensor unit 10 on the basis
of the inclined angle .alpha. of the shaft of the golf club 3.
The swing analysis portion 211 computes changes in attitudes from
the initial attitude of the sensor unit 10 in time series by
performing rotation calculation using angular velocity data which
is subsequently measured by the angular velocity sensor 14. An
attitude of the sensor unit 10 may be expressed by, for example,
rotation angles (a roll angle, a pitch angle, and a yaw angle)
about the X axis, the Y axis, and the Z axis, or a quaternion.
The signal processing section 16 of the sensor unit 10 may compute
an offset amount of measured data so as to perform bias correction
on the measured data, and the acceleration sensor 12 and the
angular velocity sensor 14 may have a bias correction function. In
this case, it is not necessary for the swing analysis portion 211
to perform bias correction on the measured data.
Detection of Swing Starting, Top and Impact Timings
First, the swing analysis portion 211 detects a timing (impact
timing) at which the user 2 hit a ball by using measured data. For
example, the swing analysis portion 211 may compute a combined
value of measured data (acceleration data or angular velocity
data), and may detect an impact timing (time point) on the basis of
the combined value.
Specifically, first, the swing analysis portion 211 computes a
combined value n.sub.0(t) of angular velocities at each time point
t by using the angular velocity data (bias-corrected angular
velocity data for each time point t). For example, if the angular
velocity data items at the time point t are respectively indicated
by x(t), y(t), and z(t), the swing analysis portion 211 computes
the combined value n.sub.0(t) of the angular velocities according
to the following Equation (2). n.sub.0(t)= {square root over
(x(t).sup.2+y(t).sup.2+z(t).sup.2)} (2)
Next, the swing analysis portion 211 converts the combined value
n.sub.0(t) of the angular velocities at each time point t into a
combined value n(t) which is normalized (scale-conversion) within a
predetermined range. For example, if the maximum value of the
combined value of the angular velocities in an acquisition period
of measured data is max (n.sub.0), the swing analysis portion 211
converts the combined value n.sub.0(t) of the angular velocities
into the combined value n(t) which is normalized within a range of
0 to 100 according to the following Equation (3).
.function..times..function..function. ##EQU00001##
Next, the swing analysis portion 211 computes a derivative dn(t) of
the normalized combined value n(t) at each time point t. For
example, if a cycle for measuring three-axis angular velocity data
items is indicated by .DELTA.t, the swing analysis portion 211
computes the derivative (difference) dn(t) of the combined value of
the angular velocities at the time point t by using the following
Equation (4). dn(t)=n(t)-n(t-.DELTA.t) (4)
FIG. 12 illustrates examples of three-axis angular velocity data
items x(t), y(t) and z(t) obtained when the user 2 hits the golf
ball 4 by performing a swing. In FIG. 12, a transverse axis
expresses time (msec), and a longitudinal axis expresses angular
velocity (dps).
FIG. 13 is a diagram in which the combined value no (t) of the
three-axis angular velocities is computed according to Equation (2)
by using the three-axis angular velocity data items x(t), y(t) and
z(t) in FIG. 12, and then the combined value n(t) normalized to 0
to 100 according to Equation (3) is displayed in a graph. In FIG.
13, a transverse axis expresses time (msec), and a longitudinal
axis expresses a combined value of the angular velocity.
FIG. 14 is a diagram in which the derivative dn(t) is calculated
according to Equation (4) on the basis of the combined value n(t)
of the three-axis angular velocities in FIG. 13, and is displayed
in a graph. In FIG. 14, a transverse axis expresses time (msec),
and a longitudinal axis expresses a derivative value of the
combined value of the three-axis angular velocities. In FIGS. 12
and 13, the transverse axis is displayed at 0 seconds to 5 seconds,
but, in FIG. 14, the transverse axis is displayed at 2 seconds to
2.8 seconds so that changes in the derivative value before and
after impact can be understood.
Next, of time points at which a value of the derivative dn(t) of
the combined value becomes the maximum and the minimum, the swing
analysis portion 211 detects the earlier time point as an impact
time point t.sub.impact (impact timing) (refer to FIG. 14). It is
considered that swing speed is the maximum at the moment of impact
in a typical golf swing. In addition, since it is considered that a
value of the combined value of the angular velocities also changes
according to a swing speed, the swing analysis portion 211 can
capture a timing at which a derivative value of the combined value
of the angular velocities is the maximum or the minimum (that is, a
timing at which the derivative value of the combined value of the
angular velocities is a positive maximum value or a negative
minimum value) in a series of swing actions as the impact timing.
Since the golf club 3 vibrates due to the impact, a timing at which
a derivative value of the combined value of the angular velocities
is the maximum and a timing at which a derivative value of the
combined value of the angular velocities is the minimum may occur
in pairs, and, of the two timings, the earlier timing may be the
moment of the impact.
Next, the swing analysis portion 211 detects a time point of a
minimum point at which the combined value n(t) is close to 0 before
the impact time point t.sub.impact, as a top time point t.sub.top
(top timing) (refer to FIG. 13). It is considered that, in a
typical golf swing, an action temporarily stops at the top after
starting the swing, then a swing speed increases, and finally
impact occurs. Therefore, the swing analysis portion 211 can
capture a timing at which the combined value of the angular
velocities is close to 0 and becomes the minimum before the impact
timing, as the top timing.
Next, the swing analysis portion 211 sets an interval in which the
combined value n(t) is equal to or smaller than a predetermined
threshold value before and after the top time point t.sub.top, as a
top interval, and detects a last time point at which the combined
value n(t) is equal to or smaller than the predetermined threshold
value before a starting time point of the top interval, as a swing
starting (backswing starting) time point t.sub.start (refer to FIG.
13). It is hardly considered that, in a typical golf swing, a swing
action is started from a standing still state, and the swing action
is stopped till the top. Therefore, the swing analysis portion 211
can capture the last timing at which the combined value of the
angular velocities is equal to or smaller than the predetermined
threshold value before the top interval as a timing of starting the
swing action. The swing analysis portion 211 may detect a time
point of the minimum point at which the combined value n(t) is
close to 0 before the top time point t.sub.top as the swing
starting time point t.sub.start.
The swing analysis portion 211 may also detect each of a swing
starting timing, a top timing, and an impact timing by using
three-axis acceleration data in the same manner.
Calculation of Shaft Plane and Hogan Plane
The shaft plane is a first virtual plane specified by a target line
(target hit ball direction) and the longitudinal direction of the
shaft of the golf club 3 at address (standing still state) of the
user 2 before starting a swing. The Hogan plane is a second virtual
plane specified by a virtual line connecting the vicinity of the
shoulder (the shoulder or the base of the neck) of the user 2 to
the head of the golf club (or the golf ball 4), and the target line
(target hit ball direction), at address of the user 2.
FIG. 15 is a diagram illustrating the shaft plane and the Hogan
plane. FIG. 15 displays the X axis, the Y axis, and the Z axis of
the XYZ coordinate system (global coordinate system).
As illustrated in FIG. 15, in the present embodiment, a virtual
plane which includes a first line segment 51 as a first axis along
a target hit ball direction and a second line segment 52 as a
second axis along the longitudinal direction of the shaft of the
golf club 3, and has four vertices such as U1, U2, S1, and S2, is
used as the shaft plane SP (first virtual plane). In the present
embodiment, the position 61 of the head of the golf club 3 at
address is set as the origin O (0,0,0) of the XYZ coordinate
system, and the second line segment 52 is a line segment connecting
the position 61 (origin O) of the head of the golf club 3 to the
position 62 of the grip end. The first line segment 51 is a line
segment having a length UL in which U1 and U2 on the X axis are
both ends, and the origin O is a midpoint. Since the user 2
performs the action in step S4 in FIG. 4 at address, and thus the
shaft of the golf club 3 is perpendicular to the target line (X
axis), the first line segment 51 is a line segment orthogonal to
the longitudinal direction of the shaft of the golf club 3, that
is, the second line segment 52. The swing analysis portion 211
calculates coordinates of the four vertices U1, U2, S1, and S2 of
the shaft plane SP in the XYZ coordinate system.
Specifically, first, the swing analysis portion 211 computes
coordinates (0,G.sub.Y,G.sub.Z) of the position 62 of the grip end
of the golf club 3 by using the inclined angle .alpha. and the
length L.sub.1 of the shaft included in the golf club information
242. As illustrated in FIG. 11, the swing analysis portion 211 may
compute G.sub.Y and G.sub.Z by using the length L.sub.1 of the
shaft and the inclined angle .alpha. according to Equations (5) and
(6). G.sub.Y=L.sub.1cos .alpha. (5) G.sub.Z=L.sub.1sin .alpha.
(6)
Next, the swing analysis portion 211 multiplies the coordinates
(0,G.sub.Y,G.sub.Z) of the position 62 of the grip end of the golf
club 3 by a scale factor S so as to compute coordinates
(0,S.sub.Y,S.sub.Z) of a midpoint S3 of the vertex S1 and the
vertex S2 of the shaft plane SP. In other words, the swing analysis
portion 211 computes S.sub.Y and S.sub.Z according to Equations (7)
and (8), respectively. S.sub.Y=G.sub.YS (7) S.sub.Z=G.sub.ZS
(8)
FIG. 16 is a view in which a sectional view of the shaft plane SP
in FIG. 15 which is cut in the YZ plane is viewed from the negative
side of the X axis. As illustrated in FIG. 16, a length (a width of
the shaft plane SP in a direction orthogonal to the X axis) of a
line segment connecting the midpoint S3 of the vertex S1 and the
vertex S2 to the origin O is S times the length L.sub.1 of the
second line segment 52. The scale factor S is set to a value at
which a trajectory of the golf club 3 during a swing action of the
user 2 enters the shaft plane SP. For example, if a length of the
arms of the user 2 is indicated by L.sub.2, the scale factor S may
be set as in Equation (9) so that the width S.times.L.sub.1 of the
shaft plane SP in the direction orthogonal to the X axis is twice
the sum of the length L.sub.1 of the shaft and the length L.sub.2
of the arms.
##EQU00002##
The length L.sub.2 of the arms of the user 2 is associated with a
height L.sub.0 of the user 2. The length L.sub.2 of the arms is
expressed by a correlation expression such as Equation (10) in a
case where the user 2 is a male, and is expressed by a correlation
expression such as Equation (11) in a case where the user 2 is a
female, on the basis of statistical information.
L.sub.2=0.41.times.L.sub.0-45.5[mm] (10)
L.sub.2=0.46.times.L.sub.0-126.9[mm] (11)
Therefore, the swing analysis portion 211 may calculate the length
L.sub.2 of the arms of the user according to Equation (10) or
Equation (11) by using the height L.sub.0 and the sex of the user 2
included in the physical information 244.
Next, the swing analysis portion 211 computes coordinates
(-UL/2,0,0) of the vertex U1 of the shaft plane SP, coordinates
(UL/2,0,0) of a vertex U2, coordinates (-UL/2,S.sub.Y,S.sub.Z) of
the vertex S1, and coordinates (UL/2,S.sub.Y,S.sub.Z) of the vertex
S2 by using the coordinates (0,S.sub.Y,S.sub.Z) of the midpoint S3
and a width (the length of the first line segment 51) UL of the
shaft plane SP in the X axis direction. The width UL in the X axis
direction is set to a value at which a trajectory of the golf club
3 during a swing action of the user 2 enters the shaft plane SP.
For example, the width UL in the X axis direction may be set to be
the same as the width S.times.L.sub.1 in the direction orthogonal
to the X axis, that is, twice the sum of the length L.sub.1 of the
shaft and the length L.sub.2 of the arms.
In the above-described manner, the swing analysis portion 211 can
calculate the coordinates of the four vertices U1, U2, S1, and S2
of the shaft plane SP.
As illustrated in FIG. 15, in the present embodiment, a virtual
plane which includes a first line segment 51 as a first axis and a
third line segment 53 as a third axis, and has four vertices such
as U1, U2, H1, and H2, is used as the Hogan plane HP (second
virtual plane). The third line segment 53 is a line segment
connecting a predetermined position 63 in the vicinity of a line
segment connecting both of the shoulders of the user 2, to the
position 61 of the head of the golf club 3. However, the third line
segment 53 may be a line segment connecting the predetermined
position 63 to a position of the golf ball 4. The swing analysis
portion 211 calculates respective coordinates of the four vertices
U1, U2, H1, and H2 of the Hogan plane HP in the XYZ coordinate
system.
Specifically, first, the swing analysis portion 211 estimates the
predetermined position 63 by using the coordinates
(0,G.sub.Y,G.sub.Z) of the position 62 of the grip end of the golf
club 3 at address (during standing still), and the length L.sub.2
of the arms of the user 2 based on the physical information 244,
and computes coordinates (A.sub.X,A.sub.Y,A.sub.Z) thereof.
FIG. 17 is a view in which a sectional view of the Hogan plane HP
illustrated in FIG. 15 which is cut in the YZ plane is viewed from
the negative side of the X axis. In FIG. 17, a midpoint of the line
segment connecting both of the shoulders of the user 2 is the
predetermined position 63, and the predetermined position 63 is
present on the YZ plane. Therefore, an X coordinate A.sub.X of the
predetermined position 63 is 0. As illustrated in FIG. 17, the
swing analysis portion 211 estimates, as the predetermined position
63, a position obtained by moving the position 62 of the grip end
of the golf club 3 by the length L.sub.2 of the arms of the user 2
in a positive direction along the Z axis. Therefore, the swing
analysis portion 211 sets a Y coordinate A.sub.Y of the
predetermined position 63 to be the same as the Y coordinate
G.sub.Y of the position 62 of the grip end. The swing analysis
portion 211 computes a Z coordinate A.sub.Z of the predetermined
position 63 as a sum of the Z coordinate G.sub.Z of the position 62
of the grip end and the length L.sub.2 of the arms of the user 2 as
in Equation (12). A.sub.Z=G.sub.Z+L.sub.2 (12)
Next, the swing analysis portion 211 multiplies the Y coordinate
A.sub.Y and the Z coordinate A.sub.Z of the predetermined position
63 by a scale factor H, so as to compute coordinates
(0,H.sub.Y,H.sub.Z) of a midpoint H3 of the vertex H1 and the
vertex H2 of the Hogan plane HP. In other words, the swing analysis
portion 211 computes H.sub.Y and H.sub.Z according to Equation (13)
and Equation (14), respectively. H.sub.Y=A.sub.YH (13)
H.sub.Z=A.sub.ZH (14)
As illustrated in FIG. 17, a length (a width of the Hogan plane HP
in a direction orthogonal to the X axis) of a line segment
connecting the midpoint H3 of the vertex H1 and the vertex H2 to
the origin O is H times the length L.sub.3 of the third line
segment 53. The scale factor H is set to a value at which a
trajectory of the golf club 3 during a swing action of the user 2
enters the Hogan plane HP. For example, the Hogan plane HP may have
the same shape and size as the shape and the size of the shaft
plane SP. In this case, the width H.times.L.sub.3 of the Hogan
plane HP in the direction orthogonal to the X axis matches the
width S.times.L.sub.1 of the shaft plane SP in the direction
orthogonal to the X axis, and is twice the sum of the length
L.sub.1 of the shaft of the golf club 3 and the length L.sub.2 of
the arms of the user 2. Therefore, the swing analysis portion 211
may compute the scale factor H according to Equation (15).
##EQU00003##
The swing analysis portion 211 may compute the length L.sub.3 of
the third line segment 53 according to Equation (13) by using the Y
coordinate A.sub.Y and the Z coordinate A.sub.Z of the
predetermined position 63.
Next, the swing analysis portion 211 computes coordinates
(-UL/2,H.sub.Y,H.sub.Z) of the vertex H1 of the Hogan plane HP, and
coordinates (UL/2, H.sub.Y, H.sub.Z) of the vertex H2 by using the
coordinates (0, H.sub.Y, H.sub.Z) of the midpoint H3 and a width
(the length of the first line segment 51) UL of the Hogan plane HP
in the X axis direction. The two vertices U1 and U2 of the Hogan
plane HP are the same as those of the shaft plane SP, and thus the
swing analysis portion 211 does not need to compute coordinates of
the vertices U1 and U2 of the Hogan plane HP again.
In the above-described manner, the swing analysis portion 211 can
calculate the coordinates of the four vertices U1, U2, H1, and H2
of the Hogan plane HP.
A region interposed between the shaft plane SP (first virtual
plane) and the Hogan plane HP (second virtual plane) is referred to
as a "V zone", and a trajectory of a hit ball (a ball line) may be
estimated to some extent on the basis of a relationship between a
position of the head of the golf club 3 and the V zone during
backswing or downswing. For example, in a case where the head of
the golf club 3 is present in a space lower than the V zone at a
predetermined timing during a backswing or downswing, a hit ball is
likely to fly in a hook direction. In a case where the head of the
golf club 3 is present in a space higher than the V zone at a
predetermined timing during a backswing or downswing, a hit ball is
likely to fly in a slice direction. In the present embodiment, as
is clear from FIG. 17, a first angle .beta. formed between the
shaft plane SP and the Hogan plane HP is determined depending on
the length L.sub.1 of the shaft of the golf club 3 and the length
L.sub.2 of the arms of the user 2. In other words, since the first
angle .beta. is not a fixed value, and is determined depending on
the type of golf club 3 or physical features of the user 2, the
more appropriate shaft plane SP and Hogan plane HP (V zone) are
calculated as an index for diagnosing a swing of the user 2.
Calculation of Head Positions at Halfway Back and Halfway Down
A head position at halfway back is a position of the head at the
moment of the halfway back, right before the halfway back, or right
after the halfway back, and a head position at halfway down is a
position of the head at the moment of the halfway down, right
before the halfway down, or right after the halfway down.
First, the swing analysis portion 211 computes a position of the
head and a position of the grip end at each time point t by using
the position and the attitude of the sensor unit 10 at each time
point t from the swing start time point t.sub.start to the impact
time point t.sub.impact.
Specifically, the swing analysis portion 211 uses a position
separated by the distance Ls in the positive direction of the y
axis specified by the attitude of the sensor unit 10, from the
position of the sensor unit 10 at each time point t as a position
of the head, and computes coordinates of the position of the head.
As described above, the distance L.sub.SH is a distance between the
sensor unit 10 and the head. The swing analysis portion 211 uses a
position separated by the distance L.sub.SG in the negative
direction of the y axis specified by the attitude of the sensor
unit 10, from the position of the sensor unit 10 at each time point
t as a position of the grip end, and computes coordinates of the
position of the grip end. As described above, the distance L.sub.SG
is a distance between the sensor unit 10 and the grip end.
Next, the swing analysis portion 211 detects a halfway back timing
and a halfway down timing by using the coordinates of the position
of the head and the coordinates of the position of the grip
end.
Specifically, the swing analysis portion 211 computes a difference
.DELTA.Z between a Z coordinate of the position of the head and a Z
coordinate of the position of the grip end at each time point t
from the swing start time point t.sub.start to the impact time
point t.sub.impact. The swing analysis portion 211 detects a time
point t.sub.HWB at which a sign of .DELTA.Z is inversed between the
swing start time point t.sub.start and the top time point
t.sub.top, as the halfway back timing. The swing analysis portion
211 detects a time point t.sub.HWD at which a sign of .DELTA.Z is
inversed between the top time point t.sub.top and the impact time
point t.sub.impact, as the halfway down timing.
The swing analysis portion 211 uses the position of the head at the
time point t.sub.HWB as a position of the head at halfway back, and
uses the position of the head at the time point t.sub.HWD as a
position of the head at halfway down.
Calculation of Head Speed
A head speed is the magnitude of a speed of the head at impact (the
moment of the impact, right before the impact, or right after the
impact). For example, the swing analysis portion 211 computes a
speed of the head at the impact time point t.sub.impact on the
basis of differences between the coordinates of the position of the
head at the impact time point t.sub.impact and coordinates of a
position of the head at the previous time point. The swing analysis
portion 211 computes the magnitude of the speed of the head as the
head speed.
Calculation of Face Angle and Club Path (Incidence Angle)
The face angle is an index based on an inclination of the head of
the golf club 3 at impact, and the club path (incidence angle) is
an index based on a trajectory of the head of the golf club 3 at
impact.
FIG. 18 is a diagram for explaining the face angle and the club
path (incidence angle). FIG. 18 illustrates the golf club 3 (only
the head is illustrated) on the XY plane viewed from a positive
side of the Z axis in the XYZ coordinate system. In FIG. 18, the
reference numeral 74 indicates a face surface (hitting surface) of
the golf club 3, and the reference numeral 75 indicates a ball
hitting point. The reference numeral 70 indicates a target line
indicating a target hit ball direction, and the reference numeral
71 indicates a plane orthogonal to the target line 70. The
reference numeral 76 indicates a curve indicating a trajectory of
the head of the golf club 3, and the reference numeral 72 is a
tangential line at the ball hitting point 75 for the curve 76. In
this case, the face angle .PHI. is an angle formed between the
plane 71 and the face surface 74, that is, an angle formed between
a straight line 73 orthogonal to the face surface 74, and the
target line 70. The club path (incidence angle) .psi. is an angle
formed between the tangential line 72 (a direction in which the
head in the XY plane passes through the ball hitting point 75) and
the target line 70.
For example, assuming that an angle formed between the face surface
of the head and the x axis direction is normally constant (for
example, orthogonal), the swing analysis portion 211 computes a
direction of a straight line orthogonal to the face surface on the
basis of the attitude of the sensor unit 10 at the impact time
point t.sub.impact. The swing analysis portion 211 uses, a straight
line obtained by setting a Z axis component of the direction of the
straight line to 0, as a direction of the straight line 73, and
computes an angle (face angle) .PHI. formed between the straight
line 73 and the target line 70.
For example, the swing analysis portion 211 uses a direction of a
speed (that is, a speed of the head in the XY plane) obtained by
setting a Z axis component of a speed of the head at the impact
time point t.sub.impact to 0, as a direction of the tangential line
72, and computes an angle (club path (incidence angle)) .psi.
formed between the tangential line 72 and the target line 70.
The face angle .PHI. indicates an inclination of the face surface
74 with the target line 70 whose direction is fixed regardless of
an incidence direction of the head to the ball hitting point 75 as
a reference, and is thus also referred to as an absolute face
angle. In contrast, an angle .eta. formed between the straight line
73 and the tangential line 72 indicates an inclination of the face
surface 74 with an incidence direction of the head to the ball
hitting point 75 as a reference, and is thus referred to as a
relative face angle. The relative face angle .eta. is an angle
obtained by subtracting the club path (incidence angle) .psi. from
the (absolute) face angle .PHI..
Calculation of Shaft Axis Rotation Angle at Top
The shaft axis rotation angle .theta..sub.top at top is an angle
(relative rotation angle) by which the golf club 3 is rotated about
a shaft axis from a reference timing to a top timing. The reference
timing is, for example, the time of starting a backswing, or the
time of address. In the present embodiment, in a case where the
user 2 is a right-handed golfer, a right-handed screw tightening
direction toward the tip end on the head side of the golf club 3 (a
clockwise direction when the head is viewed from the grip end side)
is a positive direction of the shaft axis rotation angle
.theta..sub.top. Conversely, in a case where the user 2 is a
left-handed golfer, a left-handed screw tightening direction toward
the tip end on the head side of the golf club 3 (a counterclockwise
direction when the head is viewed from the grip end side) is a
positive direction of the shaft axis rotation angle
.theta..sub.top.
FIG. 19 is a diagram illustrating an example of a temporal change
of the shaft axis rotation angle from starting of a swing (starting
of a backswing) to impact. In FIG. 19, a transverse axis expresses
time (s), and a longitudinal axis expresses a shaft axis rotation
angle (deg). FIG. 19 illustrates the shaft axis rotation angle
.theta..sub.top at top with the time of starting a swing (the time
of starting a backswing) as a reference timing (at which the shaft
axis rotation angle is 0.degree.).
In the present embodiment, as illustrated in FIG. 3, the y axis of
the sensor unit 10 substantially matches the long axis direction of
the shaft of the golf club 3 (the long axis direction of the golf
club 3). Therefore, for example, the swing analysis portion 211
time-integrates a y axis angular velocity included in angular
velocity data from the swing starting (backswing starting) time
point t.sub.start or the time of address to the top time point
t.sub.top (at top), so as to compute the shaft axis rotation angle
.theta..sub.top.
Calculation of Grip Deceleration Ratio and Grip Deceleration Time
Ratio
The grip deceleration ratio is an index based on a grip
deceleration amount, and is a ratio between a speed of the grip
when the grip starts to be decelerated during the downswing, and a
speed of the grip at impact. The grip deceleration time ratio is an
index based on a grip deceleration period, and is a ratio between a
period of time from the time at which the grip starts to be
decelerated during the downswing to the time of impact, and a
period of time of the downswing. A speed of the grip is preferably
a speed of a portion held by the user 2, but may be a speed of any
portion of the grip (for example, the grip end), and may be a speed
of a peripheral portion of the grip.
FIG. 20 is a diagram illustrating an example of a temporal change
of a speed of the grip during the downswing. In FIG. 20, a
transverse axis expresses time (s), and a longitudinal axis
expresses a speed (m/s) of the grip. In FIG. 20, if a speed (the
maximum speed of the grip) when the grip starts to be decelerated
is indicated by V1, and a speed of the grip at impact is indicated
by V2, a grip deceleration ratio R.sub.V (unit: %) is expressed by
the following Equation (16).
.times..times..times..times..times..times..times..times.
##EQU00004##
In FIG. 20, if a period of time from the time of top to the time at
which the grip starts to be decelerated is indicated by T1, and a
period of time from the time at which the grip starts to be
decelerated during the downswing to the time of impact is indicated
by T2, a grip deceleration time ratio R.sub.T (unit: %) is
expressed by the following Equation (17).
.times..times..times..times..times..times..times..times.
##EQU00005##
For example, the sensor unit 10 may be attached to the vicinity of
a portion of the golf club 3 held by the user 2, and a speed of the
sensor unit 10 may be regarded as a speed of the grip. Therefore,
first, the swing analysis portion 211 computes a speed of the
sensor unit 10 at the time point t on the basis of differences
between coordinates of a position of the sensor unit 10 at each
time point t from the top time point t.sub.top to the impact time
point t.sub.impact (during the downswing), and coordinates of a
position of the sensor unit 10 at the previous time point.
Next, the swing analysis portion 211 computes the magnitude of the
speed of the sensor unit 10 at each time point t, sets the maximum
value thereof as V1, and sets the magnitude of the speed at the
impact time point t.sub.impact as V2. The swing analysis portion
211 specifies a time point t.sub.vmax at which the magnitude of the
speed of the sensor unit 10 becomes the maximum value V1. The swing
analysis portion 211 computes T1=t.sub.vmax-t.sub.top, and
T2=t.sub.impact-t.sub.vmax. The swing analysis portion 211 computes
the grip deceleration ratio R.sub.V and the grip deceleration time
ratio R.sub.T according to Equations (16) and (17),
respectively.
The swing analysis portion 211 may regard a speed of the grip end
as a speed of the grip, and may compute the speed of the grip end
on the basis of coordinates of a position of the grip end at each
time point t during the downswing, so as to obtain the grip
deceleration ratio R.sub.V and the grip deceleration time ratio
R.sub.T through the above-described computation.
Procedures of Swing Analysis Process (Swing Analysis Method)
FIG. 21 is a flowchart illustrating examples of procedures of a
swing analysis process (swing analysis method) performed by the
processing section 21. The processing section 21 performs the swing
analysis process, for example, according to the procedures shown in
the flowchart of FIG. 21 by executing the swing analysis program
240 stored in the storage section 24. Hereinafter, the flowchart of
FIG. 21 will be described.
First, the processing section 21 waits for the user 2 to perform a
measurement starting operation (the operation in step S2 in FIG. 4)
(N in step S10), transmits a measurement starting command to the
sensor unit 10 if the measurement starting operation is performed
(Y in step S10), and starts to acquire measured data from the
sensor unit 10 (step S12).
Next, the processing section 21 instructs the user 2 to take an
address attitude (step S14). The user 2 takes the address attitude
in response to the instruction, and stands still (step S4 in FIG.
4).
Next, if a standing still state of the user 2 is detected by using
the measured data acquired from the sensor unit 10 (Y in step S16),
the processing section 21 notifies the user 2 of permission of
swing starting (step S18). The processing section 21 outputs, for
example, a predetermined sound, or an LED is provided in the sensor
unit 10, and the LED is lighted, so that the user 2 is notified of
permission of swing starting. The user 2 confirms the notification
and then starts a swing action (the action in step S6 in FIG.
4).
Next, the processing section 21 performs processes in step S20 and
subsequent steps after completion of the swing action of the user
2, or from before completion of the swing action.
First, the processing section 21 computes an initial position and
an initial attitude of the sensor unit 10 by using the measured
data (measured data during standing still (at address) of the user
2) acquired from the sensor unit 10 (step S20).
Next, the processing section 21 detects a swing starting timing, a
top timing, and an impact timing by using the measured data
acquired from the sensor unit 10 (step S22).
The processing section 21 computes a position and an attitude of
the sensor unit 10 during the swing action of the user 2 in
parallel to the process in step S22, or before and after the
process in step S22 (step S24).
Next, in steps S26 to S34, the processing section 21 computes
values of various indexes regarding the swing by using at least
some of the measured data acquired from the sensor unit 10, the
swing starting, top and impact timings detected in step S22, and
the position and the attitude of the sensor unit 10 computed in
step S24.
The processing section 21 computes the shaft plane SP and the Hogan
plane HP in step S26.
The processing section 21 computes a head position at halfway back
and a head position at halfway down in step S28.
The processing section 21 computes a head speed, the face angle
.PHI., and the club path (incidence angle) .psi. in step S30.
The processing section 21 computes the shaft axis rotation angle
.theta..sub.top at top in step S32.
The processing section 21 computes the grip deceleration ratio
R.sub.V and the grip deceleration time ratio R.sub.T in step
S34.
The processing section 21 generates the swing analysis data 248 by
using the various indexes calculated in steps S26 to S34, transmits
the swing analysis data to the swing diagnosis apparatus 30 (step
S36), and finishes the swing analysis process.
In the flowchart of FIG. 21, order of the respective steps may be
changed as appropriate within an allowable range, some of the steps
may be omitted or changed, and other steps may be added
thereto.
1-4. Configuration of Swing Diagnosis Apparatus
FIG. 22 is a diagram illustrating a configuration example of the
swing diagnosis apparatus 30. As illustrated in FIG. 22, in the
present embodiment, the swing diagnosis apparatus 30 is configured
to include a processing section 31, a communication section 32, and
a storage section 34. However, the swing diagnosis apparatus 30 may
have a configuration in which some of the constituent elements are
deleted or changed as appropriate, or may have a configuration in
which other constituent elements are added thereto.
The storage section 34 is constituted of, for example, various IC
memories such as a ROM, a flash ROM, and a RAM, or a recording
medium such as a hard disk or a memory card. The storage section 34
stores a program for the processing section 31 performing various
calculation processes or a control process, or various programs or
data for realizing application functions.
In the present embodiment, the storage section 34 stores a swing
diagnosis program 340 which is read by the processing section 31
and executes a swing diagnosis process. The swing diagnosis program
340 may be stored in a nonvolatile recording medium (computer
readable recording medium) in advance, or the swing diagnosis
program 340 may be received from a server (not illustrated) by the
processing section 31 via a network, and may be stored in the
storage section 34.
In the present embodiment, the storage section 34 stores
(preserves) a swing analysis data list 341 including a plurality of
items of swing analysis data 248 generated by the swing analysis
apparatus 20. In other words, the swing analysis data 248 generated
whenever the processing section 21 of the swing analysis apparatus
20 analyzes a swing action of the user 2 is sequentially added to
the swing analysis data list 341.
In the present embodiment, the storage section 34 stores a V zone
score table 342, a rotation score table 343, an impact score table
344, a speed score table 345, and a swing efficiency score table
346. The score tables will be described later in detail.
The storage section 34 is used as a work area of the processing
section 31, and temporarily stores results of calculation executed
by the processing section 31 according to various programs, and the
like. The storage section 34 may store data which is required to be
preserved for a long period of time among data items generated
through processing of the processing section 31.
The communication section 32 performs data communication with the
communication section 27 (refer to FIG. 10) of the swing analysis
apparatus 20 via the network 40. For example, the communication
section 32 performs a process of receiving the swing analysis data
248 from the communication section 27 of the swing analysis
apparatus 20, and transmitting the swing analysis data 248 to the
processing section 31. For example, the communication section 32
performs a process of transmitting information required to display
the selection screen illustrated in FIG. 7 to the communication
section 27 of the swing analysis apparatus 20, or a process of
receiving selected information on the selection screen illustrated
in FIG. 7 from the communication section 27 of the swing analysis
apparatus 20 and transmitting the selected information to the
processing section 31. For example, the communication section 32
performs a process of receiving information required to display the
input data editing screen illustrated in FIG. 8 from the processing
section 31, and transmitting the information to the communication
section 27 of the swing analysis apparatus 20. For example, the
communication section 32 performs a process of receiving input data
at the time of the diagnosis starting button on the input data
editing screen illustrated in FIG. 8 being pressed from the
communication section 27 of the swing analysis apparatus 20,
transmitting the input data to the processing section 31, receiving
diagnosis result information (scores or a total score of a
plurality of items indicating features of a swing of the user 2)
based on the input data from the processing section 31, and
transmitting the diagnosis result information to the communication
section 27 of the swing analysis apparatus 20. For example, the
communication section 32 performs a process of receiving
information required to display the swing diagnosis screen
illustrated in FIG. 9 from the processing section 31, and
transmitting the information to the communication section 27 of the
swing analysis apparatus 20.
The processing section 31 performs a process of receiving the swing
analysis data 248 from the swing analysis apparatus 20 via the
communication section 32 and storing the swing analysis data 248 in
the storage section 34 (adding the swing analysis data to the swing
analysis data list 341), according to various programs. The
processing section 31 performs a process of receiving various
pieces of information from the swing analysis apparatus 20 via the
communication section 32, and transmitting information required to
display various screens (the respective screens illustrated in
FIGS. 7, 8 and 9) to the swing analysis apparatus 20, according to
various programs. The processing section 31 performs other various
control processes.
Particularly, in the present embodiment, the processing section 31
functions as a data acquisition portion 310, a score calculation
portion 311, and a storage processing portion 312 by executing the
swing diagnosis program 340, and performs a diagnosis process
(swing diagnosis process) on the swing analysis data 248 selected
from the swing analysis data list 341.
The data acquisition portion 310 performs a process of receiving
the swing analysis data 248 received from the swing analysis
apparatus 20 by the communication section 32 and transmitting the
swing analysis data 248 to the storage processing portion 312. The
data acquisition portion 310 performs a process of receiving
various pieces of information received from the swing analysis
apparatus 20 by the communication section 32 and transmitting the
information to the score calculation portion 311.
The storage processing portion 312 performs read/write processes of
various programs or various data for the storage section 34. The
storage processing portion 312 performs a process of receiving the
swing analysis data 248 from the data acquisition portion 310 and
storing the swing analysis data 248 in the storage section 34
(adding the swing analysis data to the swing analysis data list
341), a process of reading the swing analysis data 248 from the
swing analysis data list 341 stored in the storage section 34, or
the like. For example, the storage processing portion 312 performs
a process of reading the V zone score table 342, the rotation score
table 343, the impact score table 344, the speed score table 345,
and the swing efficiency score table 346 stored in the storage
section 34.
The score calculation portion 311 (level calculation section)
performs a process of calculating scores (levels) of a plurality of
items on the basis of data regarding a swing. In the present
embodiment, the data regarding a swing may be input data at the
time of the diagnosis starting button on the input data editing
screen illustrated in FIG. 8 being pressed, may be the swing
analysis data 248 selected on the selection screen illustrated in
FIG. 7, and may include both of the data.
For example, in a case where the sex, the type of golf club, and
each index of a swing are not edited in a state of being initial
values, and the diagnosis starting button is pressed on the input
data editing screen illustrated in FIG. 8, the score calculation
portion 311 performs a process of calculating scores on the basis
of the swing analysis data 248 selected from the swing analysis
data list 341. On the other hand, in a case where at least one of
the sex, the type of golf club, and each index of a swing is
edited, and then the diagnosis starting button is pressed on the
input data editing screen illustrated in FIG. 8, the score
calculation portion 311 performs a process of calculating scores on
the basis of data (pseudo-data) in which at least a part of the
selected swing analysis data 248 is edited.
A plurality of items which are score calculation targets include a
first item regarding at least one of a backswing and a downswing.
The first item may include an item indicating a relationship among
at least one virtual plane, a position of the head (an example of a
ball hitting portion) of the golf club 3 (an example of an exercise
appliance) at a first timing during the backswing, and a position
of the head at a second timing during the downswing. For example,
the first timing may be the time at which the long axis direction
of the golf club 3 becomes a direction along the horizontal
direction during the backswing. For example, the second timing may
be the time at which the long axis direction of the golf club 3
becomes a direction along the horizontal direction during the
downswing.
At least one virtual plane may include the shaft plane SP which is
a first virtual plane specified on the basis of the first line
segment 51 which is a first axis along a target hit ball direction
(target line) in the XY plane as a reference plane, and the second
line segment 52 which is a second axis along the long axis
direction of the golf club 3 before starting a backswing. The time
before starting a backswing may be the time of address (when the
user 2 takes an address attitude and stands still).
At least one virtual plane may include the Hogan plane HP which is
a second virtual plane (that is, the second virtual plane forms a
first angle .beta. with the first virtual plane) specified on the
basis of the first line segment 51 which is a first axis along a
target hit ball direction (target line) in the XY plane as a
reference plane, and the third line segment 53 which is a third
axis forming the first angle .beta. with the long axis direction of
the golf club 3 before starting a backswing.
At least one virtual plane may include only one of the shaft plane
SP and the Hogan plane HP. At least one virtual plane may include
other virtual planes (for example, a plane interposed between the
shaft plane SP and the Hogan plane HP, a plane outside the shaft
plane SP and the Hogan plane HP, and a plane intersecting at least
one of the shaft plane SP and the Hogan plane HP) instead of the
shaft plane SP or the Hogan plane HP.
Hereinafter, the first item is assumed to include an item
(hereinafter, this item will be referred to as a "V zone" item)
indicating a relationship among four indexes of a swing, that is,
the "shaft plane SP", the "Hogan plane HP", a "position of the head
at halfway back", and a "position of the head at halfway down".
The first item may include an item regarding swing efficiency. The
item regarding swing efficiency may be an item indicating a
relationship between a deceleration amount and a deceleration
period of the grip (an example of a holding portion) of the golf
club 3 in a downswing. Hereinafter, the first item is assumed to
include an item (hereinafter, this item will be referred to as a
"swing efficiency" item) indicating a relationship between a "grip
deceleration ratio" which is an index based on the deceleration
amount of the grip and a "grip deceleration time ratio" which is an
index based on the deceleration period of the grip, as the item
regarding swing efficiency.
The plurality of items which are score calculation targets also
include a second item regarding impact (at ball hitting). The
second item may include an item indicating a relationship between
an incidence angle of the head of the golf club 3 and an
inclination of the head at impact (at ball hitting). Hereinafter,
the second item is assumed to include an item (hereinafter, this
item will be referred to as an "impact" item) indicating a
relationship between the "club path (incidence angle) .psi." which
is an index based on the incidence angle of the head of the golf
club 3 at impact and the "relative face angle .eta." which is an
index based on the inclination of the head at impact.
The second item may include an item regarding a speed of the golf
club 3 at impact (at ball hitting). Hereinafter, the second item is
assumed to include an item (hereinafter, this item will be referred
to as a "speed" item) indicating a relationship among a "head
speed" which is an index based on the speed of the golf club 3 at
impact, a "sex", and the "type of golf club 3".
The plurality of items which are score calculation targets may also
include a third item regarding the time at which a swing
transitions from a backswing to a downswing, and the time of impact
(the time of ball hitting). The third item may include an item
indicating a relationship between a rotation angle about the long
axis direction of the golf club 3 at the time (at top) at which a
swing transitions from a backswing to a downswing and an
inclination of the head of the golf club 3 at impact (at ball
hitting). Hereinafter, the third item is assumed to include an item
(hereinafter, this item will be referred to as a "rotation" item)
indicating a relationship between the "shaft axis rotation angle
.theta..sub.top at top" which is an index based on the rotation
angle about the long axis direction of the golf club 3 at the top
timing, and the "(absolute) face angle .PHI." which is an index
based on the inclination of the head at impact.
The score calculation portion 311 performs a process of calculating
a total score on the basis of the scores of the plurality of items.
The processing section 31 transmits information regarding the
scores or the total score of the plurality of items, calculated by
the score calculation portion 311, to the swing analysis apparatus
20 via the communication section 32. In other words, the processing
section 31 also functions as an output section which outputs the
information regarding the scores (levels) or the total score of the
plurality of items.
1-5. Swing Diagnosis Process
In the present embodiment, the processing section 31 of the swing
diagnosis apparatus 30 performs a process of calculating scores and
a total score of a plurality of items indicating features of a
swing as a swing analysis process.
A detailed description will be made of a method of calculating a
score of each item and a method of calculating a total score in the
score calculation portion 311 of the processing section 31.
Calculation of Score of "V Zone" Item
The score calculation portion 311 calculates a score of the "V
zone" item depending on in which regions head positions at halfway
back and halfway down are included among a plurality of regions
determined based on the shaft plane SP and the Hogan plane HP (V
zone).
FIG. 23 is a diagram illustrating examples of relationships among
the shaft plane SP and the Hogan plane HP (V zone), and a plurality
of regions. FIG. 23 illustrates relationships among the shaft plane
SP, the Hogan plane HP, and five regions A to E when viewed from a
negative side of the X axis (when projected onto the YZ plane). The
region B is a predetermined space including the Hogan plane HP, and
the region D is a predetermined space including the shaft plane SP.
The region C is a space interposed between the region B and the
region D (a space between an interface S.sub.BC with region B and
an interface S.sub.CD with the region D). The region A is a space
in contact with the region B in an interface SA on an opposite side
to the region C. The region E is a space in contact with the region
D in an interface S.sub.DE on an opposite side to the region C.
There may be various methods of setting the interface S.sub.AB, the
interface S.sub.BC, the interface S.sub.CD, and the interface
S.sub.DE. As an example, the interfaces may be set so that, on the
YZ plane, the Hogan plane HP is located exactly at the center of
the interface S.sub.AB and the interface S.sub.BC, the shaft plane
SP is located exactly at the center of the interface S.sub.CD and
the interface S.sub.DE, and angles of the region B, the region C,
and the region D about the origin O (X axis) are the same as each
other. In other words, with respect to the first angle .beta.
formed between the shaft plane SP and the Hogan plane HP, if each
of angles formed between the Hogan plane HP, and the interface
S.sub.AB and the interface S.sub.BC is set to .beta./4, and each of
angles formed between the shaft plane SP, and the interface
S.sub.CD and the interface S.sub.DE is set to .beta./4, angles of
the region B, the region C, and the region D are all set to
.beta./2.
Since a swing that causes a Y coordinate of a head position at
halfway back or halfway down to be negative cannot be expected, an
interface of the region A opposite to the interface S.sub.AB is set
in the XZ plane in FIG. 23. Similarly, a swing that causes a Z
coordinate of a head position at halfway back or halfway down to be
negative cannot be expected, and an interface of the region E
opposite to the interface S.sub.DE is set in the XY plane. Of
course, an interface of the region A or the region E may be set so
that an angle of the region A or the region E about the origin O (X
axis) is the same as angles of the region B, the region C, and the
region D.
Specifically, first, the score calculation portion 311 sets the
interface S.sub.AB, the interface S.sub.B, the interface S.sub.CD,
and the interface S.sub.DE of the regions A to E on the basis of
coordinates of each of the four vertices U1, U2, S1, and S2 of the
shaft plane SP and coordinates of each of the four vertices U1, U2,
H1, and H2 of the Hogan plane HP, included in data (selected swing
analysis data 248) regarding a swing. Next, the score calculation
portion 311 determines in which region of the regions A to E
coordinates of a head position at halfway back and coordinates of a
head position at halfway down included in the data (selected swing
analysis data 248) regarding the swing are included. Information
regarding a determination result thereof is transmitted to the
swing analysis apparatus 20, and is used as the information
regarding the "sex" and the "region in which a head position at
halfway down is included" in the input data editing screen
illustrated in FIG. 8. Thereafter, the score calculation portion
311 calculates a score corresponding to the determination result by
referring to the V zone score table 342 and by using information
regarding a "region in which a head position at halfway back is
included" and a "region in which a head position at halfway down is
included", included in the data (diagnosis target input data)
regarding the swing.
In the present embodiment, as illustrated in FIG. 24, the V zone
score table 342 defines a score for each combination of the region
in which a head position at halfway back is included and the region
in which a head position at halfway down is included. For example,
in a case where a head position at halfway back is included in the
region A, and a head position at halfway down is included in the
region A, a score is pv1. Each of scores pv1 to pv25 illustrated in
FIG. 24 is any one of, for example, 1 point to 5 points.
The score calculation portion 311 may calculate a lower score as a
hit ball predicted on the basis of a relationship among the shaft
plane SP, the Hogan plane HP, the head position at halfway back,
and the head position at halfway down becomes more easily curved.
The term "easily curved" may indicate that a trajectory after ball
hitting is easily curved (easily sliced or hooked), and may
indicate that a hit ball direction is easily deviated relative to a
target direction (target line). Alternatively, the score
calculation portion 311 may calculate a higher score as a hit ball
more easily flies straight. The term "easily flies straight" may
indicate that a trajectory after ball hitting is hardly curved
(easily straightened), and may indicate that a hit ball direction
is hardly deviated relative to a target direction (target
line).
For example, in a case where a head position at halfway back is
included in the region E, and a head position at halfway down is
included in the region A, it is expected that a hit ball is easily
curved, and thus the score calculation portion 311 calculates a
relatively low score. Therefore, in the example illustrated in FIG.
24, pv21 may be 1 point which is the lowest score, for example,
among 1 point to 5 points.
For example, in a case where a head position at halfway back and a
head position at halfway down are all included in the region C, it
is expected that a hit ball easily flies straight, and thus the
score calculation portion 311 calculates a relatively high score
(for example, 5 points maximum). Therefore, in the example
illustrated in FIG. 24, pv13 may be 5 points which is the highest
score, for example, among 1 point to 5 points.
Calculation of Score of "Rotation" Item
The score calculation portion 311 calculates a score of the
"rotation" item depending on in which range among a plurality of
ranges each of the shaft axis rotation angle .theta..sub.top at top
and the face angle .PHI. is included. Specifically, first, the
score calculation portion 311 determines whether or not in which
range each of the shaft axis rotation angle .theta..sub.top at top
and the face angle .PHI. included in data (target diagnosis input
data) regarding a swing is included. Next, the score calculation
portion 311 calculates a score corresponding to a determination
result by referring to the rotation score table 343.
In the present embodiment, as illustrated in FIG. 25, the rotation
score table 343 defines a score for each combination of a range in
which the shaft axis rotation angle .theta..sub.top at top is
included and a range in which the face angle .PHI. is included. In
the example illustrated in FIG. 25, a range in which the shaft axis
rotation angle .theta..sub.top at top is included is classified
into five ranges such as "less than .theta.1", ".theta.1 or more
and less than .theta.2", ".theta.2 or more and less than .theta.3",
".theta.3 or more and less than .theta.4", and ".theta.4 or more".
A range in which the face angle .PHI. is included is classified
into seven ranges such as "less than .PHI.1", ".PHI.1 or more and
less than .PHI.2", ".PHI.2 or more and less than .PHI.3", ".PHI.3
or more and less than .PHI.4", ".PHI.4 or more and less than
.PHI.5", ".PHI.5 or more and less than .PHI.6", and ".PHI.6 or
more". For example, in a case where the shaft axis rotation angle
.theta..sub.top at top is included in the range of "less than
.theta.1", and the face angle .PHI. is included in the range of
"less than .PHI.1", a score is pr1. Each of scores pr1 to pr35
illustrated in FIG. 25 is any one of, for example, 1 point to 5
points.
The score calculation portion 311 may calculate a lower score as a
hit ball predicted on the basis of a relationship between the shaft
axis rotation angle .theta..sub.top at top and the face angle .PHI.
becomes more easily curved.
For example, since the face surface of the golf club 3 is
considerably open in a state where the shaft axis rotation angle
.theta..sub.top at top is extremely large, it is expected that the
face surface is not completely returned to a square at impact, and
thus a hit ball is easily curved. A state in which the face angle
.PHI. is extremely large is a state in which the face surface at
impact is considerably open, and a state in which the face angle
.PHI. is extremely small (a negative state in which an absolute
value thereof is great) is a state in which the face surface at
impact is considerably closed. In either state, it is expected that
a hit ball is easily curved. In other words, for example, in a case
where the shaft axis rotation angle .theta..sub.top is included in
the range of ".PHI.4 or more", and the face angle .PHI. is included
in the range of "less than .PHI.1" or ".PHI.6 or more", it is
expected that a hit ball is easily curved, and thus the score
calculation portion 311 calculates a relatively low score.
Therefore, in the example illustrated in FIG. 25, pr29 or pr35 may
be 1 point which is the lowest score, for example, among 1 point to
5 points.
For example, if the shaft axis rotation angle .theta..sub.top at
top is small, it is expected that the face surface is completely
returned to the square at impact, and thus a hit ball easily flies
straight. If the face angle .PHI. is close to 0.degree., the face
surface at impact is close to the square, and thus it is expected
that a hit ball easily flies straight. In other words, in a case
where the shaft axis rotation angle .theta..sub.top is included in
the range of "less than .theta.1", and the face angle .PHI. is
included in the range of ".PHI.3 or more and less than .PHI.4", it
is expected that a hit ball easily flies straight, and thus the
score calculation portion 311 calculates a relatively high score
(for example, 5 points maximum). Therefore, in the example
illustrated in FIG. 25, pr4 may be 5 points which is the highest
score, for example, among 1 point to 5 points.
Calculation of Score of "Impact" Item
The score calculation portion 311 calculates a score of the
"impact" item depending on in which range among a plurality of
ranges each of the club path (incidence angle) .psi. and the
relative face angle .eta. is included. Specifically, first, the
score calculation portion 311 determines whether or not in which
range the club path (incidence angle) .psi. included in data
(target diagnosis input data) regarding a swing is included. The
score calculation portion 311 calculates the relative face angle
.eta. by subtracting the club path (incidence angle) .psi. from the
face angle .PHI. included in the data (diagnosis target input data)
regarding the swing (refer to FIG. 18), and determines in which
range the relative face angle .eta. is included. Next, the score
calculation portion 311 calculates a score corresponding to a
determination result by referring to the impact score table
344.
In the present embodiment, as illustrated in FIG. 26, the impact
score table 344 defines a score for each combination of a range in
which the relative face angle .eta.is included and a range in which
the club path (incidence angle) .psi. is included. In the example
illustrated in FIG. 26, a range in which the relative face angle
.eta. is included is classified into five ranges such as ".eta.1 or
more", "less than .eta.1 and .eta.2 or more", "less than .eta.2 and
.eta.3 or more", "less than .eta.3 and .eta.4 or more", and "less
than .eta.4". A range in which the club path (incidence angle)
.psi. is included is classified into five ranges such as "less than
.psi.1", ".psi.1 or more and less than .psi.2", ".psi.2 or more and
less than .psi.3", ".psi.3 or more and less than .psi.4", and
".psi.4 or more". For example, in a case where the relative face
angle .eta. is included in the range of ".eta.1 or more", and the
club path (incidence angle) w is included in the range of "less
than .psi.1", a score is pi1. Each of scores pi1 to pi25
illustrated in FIG. 26 is any one of, for example, 1 point to 5
points.
The score calculation portion 311 may calculate a lower score as a
hit ball predicted on the basis of a relationship between the club
path (incidence angle) .psi. and the relative face angle .eta.
becomes more easily curved.
For example, a state in which the relative face angle .eta. is
extremely large is a state in which the face surface at impact is
open, and a state in which the face angle .PHI. is extremely small
(a negative state in which an absolute value thereof is great) is a
state in which the face surface at impact is considerably closed.
In either state, it is expected that a hit ball is easily curved.
For example, in a state in which the club path (incidence angle)
.psi. is extremely large, a trajectory of the head at impact
becomes a considerably inside-out trajectory, and it is expected
that a hit ball is easily curved. In a state in which the club path
(incidence angle) .psi. is extremely small (a negative state in
which an absolute value thereof is great), a trajectory of the head
at impact becomes a considerably outside-in trajectory, and it is
expected that a hit ball is easily curved. In other words, for
example, in a case where the relative face angle .eta. is included
in the range of ".eta.1 or more" or "less than .eta.4", and the
club path (incidence angle) .psi. is included in the range of "less
than .psi.1" or ".psi.4 or more", it is expected that a hit ball is
easily curved, and thus the score calculation portion 311
calculates a relatively low score. Therefore, in the example
illustrated in FIG. 26, pi1, pi5, pi21, and pi25 may be 1 point
which is the lowest score, for example, among 1 point to 5
points.
For example, in a case where the relative face angle .eta. is close
to 0.degree., and the club path (incidence angle) W is close to
0.degree., the face surface at impact is close to the square, and a
trajectory of the head at impact is nearly straight. Therefore, it
is expected that a hit ball easily flies straight. In other words,
in a case where the relative face angle .eta. is included in the
range of "less than .eta.2 and .eta.3 or more", and the club path
(incidence angle) .psi. is included in the range of ".psi.2 or more
and less than .psi.3", it is expected that a hit ball easily flies
straight, and thus the score calculation portion 311 calculates a
relatively high score (for example, 5 points maximum). Therefore,
in the example illustrated in FIG. 26, pi13 may be 5 points which
is the highest score, for example, among 1 point to 5 points.
Calculation of Score of "Speed" Item
The score calculation portion 311 calculates a score of the "speed"
item depending on in which range among a plurality of ranges a head
speed is included. However, a head speed differs depending on males
and females, and, generally, there is a tendency that a head speed
of the males is high. A head speed differs depending on a driver or
an iron, and, generally, there is a tendency that a head speed of
the driver is high. Thus, it is preferable to select a plurality of
set ranges for classifying a head speed on the basis of the sex or
the type of golf club. Specifically, first, the score calculation
portion 311 determines whether the user 2 is a male or a female,
and whether the golf club 3 which is used is a driver or an iron,
on the basis of information regarding the sex of the user 2 and
information regarding the type of golf club 3 included in data
(selected swing analysis data 248 or the like) regarding a swing.
Information regarding a determination result is transmitted to the
swing analysis apparatus 20, and is used as the information
regarding a "sex" and the "type of golf club" on the input data
editing screen illustrated in FIG. 8. Then, the score calculation
portion 311 selects of a plurality of set ranges for classifying a
head speed by using information regarding the "sex" and the "type
of golf club" included in data (diagnosis target input data)
regarding a swing. Next, the score calculation portion 311
determines in which range among a plurality of ranges a head speed
included in the data (diagnosis target input data) regarding the
swing is included. Next, the score calculation portion 311
calculates a score corresponding to a determination result by
referring to the speed score table 345. The score calculation
portion 311 may calculate a lower score as a head speed becomes
lower.
In the present embodiment, as illustrated in FIG. 27, the speed
score table 345 defines a plurality of ranges which are set
depending on a "male" or a "female", and a "driver" or an "iron",
and a score of a range in which a head speed is included for each
of the plurality of set ranges. In the example illustrated in FIG.
27, in a case of a "male" and a "driver", a range in which a head
speed is included is classified into five ranges such as "less than
vh1", "vh1 or more and less than vh2", "vh2 or more and less than
vh3", "vh3 or more and less than vh4", and "vh4 or more". In a case
of a "male" and an "iron", a range in which a head speed is
included is classified into five ranges such as "less than vh5",
"vh5 or more and less than vh6", "vh6 or more and less than vh7",
"vh7 or more and less than vh8", and "vh8 or more". In a case of a
"female" and a "driver", a range in which a head speed is included
is classified into five ranges such as "less than vh11", "vh11 or
more and less than vh12", "vh12 or more and less than vh13", "vh13
or more and less than vh14", and "vh14 or more". In a case of a
"female" and an "iron", a range in which a head speed is included
is classified into five ranges such as "less than vh15", "vh15 or
more and less than vh16", "vh16 or more and less than vh17", "vh17
or more and less than vh18", and "vh18 or more". For example, in a
case of a "male" and a "driver", if a head speed is included in the
range of "less than vh1", a score is 1 point which is the lowest
score among 1 point to 5 points. If a head speed is included in the
range of "vh4 or more", a score is 5 points which is the highest
score among 1 point to 5 points. For example, in a case of a
"female" and an "iron", if a head speed is included in the range of
"less than vh15", a score is 1 point which is the lowest score
among 1 point to 5 points. If a head speed is included in the range
of "vh18 or more", a score is 5 points which is the highest score
among 1 point to 5 points.
Calculation of Score of "Swing Efficiency" Item
The score calculation portion 311 calculates a score of the "swing
efficiency" item depending on in which range among a plurality of
ranges each of the grip deceleration ratio R.sub.V and the grip
deceleration time ratio R.sub.T is included. Specifically, first,
the score calculation portion 311 determines whether or not in
which range each of the grip deceleration ratio R.sub.V and the
grip deceleration time ratio R.sub.T included in data (target
diagnosis input data) regarding a swing is included. Next, the
score calculation portion 311 calculates a score corresponding to a
determination result by referring to the swing efficiency score
table 346.
In the present embodiment, as illustrated in FIG. 28, the swing
efficiency score table 346 defines a score for each combination of
a range in which the grip deceleration ratio R.sub.V is included
and a range in which the grip deceleration time ratio R.sub.T is
included. In the example illustrated in FIG. 28, a range in which
the grip deceleration ratio R.sub.V is included is classified into
six ranges such as "nu1 or more", "less than nu1 and nu2 or more",
"less than nu2 and nu3 or more", "less than nu3 and nu4 or more",
"less than nu4 and nu5 or more" and "less than nu5". A range in
which the grip deceleration time ratio R.sub.T is included is
classified into six ranges such as "nup1 or more", "less than nup1
and nup2 or more", "less than nup2 and nup3 or more", "less than
nup3 and nup4 or more", "less than nup4 and nup5 or more", and
"less than nup5". For example, in a case where the grip
deceleration ratio R.sub.V is included in the range of "nu1 or
more", and the grip deceleration time ratio R.sub.T is included in
the range of "nup1 or more", a score is ps1. Each of scores ps1 to
ps36 illustrated in FIG. 28 is any one of, for example, 1 point to
5 points.
The score calculation portion 311 may calculate a higher score as
swing efficiency predicted on the basis of the grip deceleration
ratio R.sub.V and the grip deceleration time ratio R.sub.T becomes
higher.
It is considered in a golf swing that, when the head is
accelerated, the arms are decelerated by reducing forces of the
arms in a downswing, and thus natural rotation of the golf club
occurs, so that the shaft is accelerated. A tendency for the
natural rotation of the golf club to occur can be understood
depending on to what extent a speed of the grip is decelerated
during a downswing. Therefore, it is expected that a highly
efficient swing using natural rotation of the golf club can be
realized as the grip deceleration ratio R.sub.V becomes higher.
However, if a timing at which natural rotation of the golf club
occurs is close to an impact timing, that is, the grip deceleration
time ratio R.sub.T is low, impact occurs in a state in which the
natural rotation of the golf club cannot be sufficiently used, and
thus it cannot necessarily be said that a highly efficient swing is
performed. In other words, for example, in a case where the grip
deceleration ratio R.sub.V is included in the range of "nu1 or
more", and the grip deceleration time ratio R.sub.T is included in
the range of "nup1 or more", it is expected that swing efficiency
is high, and thus the score calculation portion 311 calculates a
relatively high score. For example, in a case where the grip
deceleration ratio R.sub.V is included in the range of "less than
nu5", and the grip deceleration time ratio R.sub.T is included in
the range of "less than nup5", it is expected that swing efficiency
is low, and thus the score calculation portion 311 calculates a
relatively low score. Therefore, in the example illustrated in FIG.
28, pal may be 5 points which is the highest score, for example,
among 1 point to 5 points, and ps36 may be 1 point which is the
lowest score, for example, among 1 point to 5 points.
Calculation of Total Score
The score calculation portion 311 calculates a total score on the
basis of the score of the "V zone" item, the score of the
"rotation" item, the score of the "impact" item, the score of the
"speed" item, and the score of the "swing efficiency" item.
For example, in a case where a score of each item is 5 points
maximum, if a maximum of a total score is 100 points, the score
calculation portion 311 may multiply the score of each item by 4 so
that 20 points maximum is obtained, and may add all the scores
together so as to calculate a total score. In the swing diagnosis
screen illustrated in FIG. 9, a score of 5 points maximum of each
item is displayed as a radar chart, and the score of each item is
multiplied by 4, and 64 points obtained by adding all the scores
together is a total score.
For example, the score calculation portion 311 may increase a
weight of a highly important item in diagnosis (evaluation) of a
swing and may add scores of the items together so as to calculate a
total score.
Procedures of Swing Diagnosis Process (Swing Diagnosis Method)
FIG. 29 is a flowchart illustrating examples of procedures of a
process performed by the processing section 21 of the swing
analysis apparatus 20 in relation to the swing diagnosis process.
FIG. 30 is a flowchart illustrating examples of procedures of the
swing diagnosis process (swing diagnosis method) performed by the
processing section 31 of the swing diagnosis apparatus 30. The
processing section 31 (an example of a computer) of the swing
diagnosis apparatus 30 performs the swing diagnosis process, for
example, according to the procedures of the flowchart of FIG. 30 by
executing the swing diagnosis program 340 stored in the storage
section 34. Hereinafter, the flowcharts of FIGS. 29 and 30 will be
described.
First, the processing section 21 of the swing analysis apparatus 20
transmits user identification information allocated to the user 2,
to the swing diagnosis apparatus 30 (step S100 in FIG. 29).
Next, the processing section 31 of the swing diagnosis apparatus 30
receives the user identification information, and transmits list
information of the swing analysis data 248 corresponding to the
user identification information (step S200 in FIG. 30).
Next, the processing section 21 of the swing analysis apparatus 20
receives the list information of the swing analysis data 248, and
displays a selection screen (FIG. 7) of the swing analysis data on
the display section 25 (step S110 in FIG. 29).
The processing section 21 of the swing analysis apparatus 20 waits
for the swing analysis data 248 to be selected on the selection
screen of the swing analysis data (N in step S120 in FIG. 29), and
transmits selected information of the swing analysis data to the
swing diagnosis apparatus 30 (step S130 in FIG. 29) if the
information is selected (Y in step S120 in FIG. 29).
Next, the processing section 31 of the swing diagnosis apparatus 30
receives the selected information of the swing analysis data (step
S210 in FIG. 30), and determines the sex (a male or a female) and
the type of golf club (a driver or an iron) on the basis of the
swing analysis data 248 which is selected on the basis of the
selected information (step S220 in FIG. 30).
The processing section 31 of the swing diagnosis apparatus 30
determines a region in which a head position at halfway back is
included and a region in which a head position at halfway down is
included on the basis of the selected swing analysis data 248 (step
S230 in FIG. 30).
Next, the processing section 31 of the swing diagnosis apparatus 30
transmits various pieces of information based on the selected swing
analysis data (step S240 in FIG. 30). The various pieces of
information based on the selected swing analysis data include the
determination result in step S220, the determination result in step
S230, and information regarding some index values (the face angle
.PHI., the club path (incidence angle) .psi., the shaft axis
rotation angle .theta..sub.top at top, the head speed, the grip
deceleration ratio R.sub.V, and the grip deceleration time ratio
R.sub.T) included in the selected swing analysis data 248.
Next, the processing section 21 of the swing analysis apparatus 20
receives the various pieces of information based on the selected
swing analysis data 248, and displays an editing screen (FIG. 8) of
input data on the display section 25 (step S140 in FIG. 29).
The processing section 21 of the swing analysis apparatus 20 waits
for a diagnosis starting operation to be performed on the editing
screen of input data (N in step S150 in FIG. 29), and transmits
diagnosis target input data to the swing diagnosis apparatus 30
(step S160 in FIG. 29) if the diagnosis starting operation is
performed (Y in step S150 in FIG. 29).
Next, the processing section 31 of the swing diagnosis apparatus 30
receives the diagnosis target input data (step S250 in FIG. 30),
and calculates scores and a total score of a plurality of items on
the basis of the diagnosis target input data (step S260 in FIG.
30).
Next, the processing section 31 of the swing diagnosis apparatus 30
transmits (outputs) information regarding the scores and the total
score of the plurality of items to the swing analysis apparatus 20
(step S270 in FIG. 30), and finishes the swing diagnosis
process.
The processing section 21 of the swing analysis apparatus 20
receives the information regarding the scores and the total score
of the plurality of items, displays the swing diagnosis screen
(FIG. 9) on the display section 25 (step S170 in FIG. 29), and
finishes the process.
In the flowchart of FIG. 29, order of the respective steps may be
changed as appropriate within an allowable range, some of the steps
may be omitted or changed, and other steps may be added thereto.
Similarly, in the flowchart of FIG. 30, order of the respective
steps may be changed as appropriate within an allowable range, some
of the steps may be omitted or changed, and other steps may be
added thereto.
FIG. 31 is a flowchart illustrating examples of procedures of a
process (step S260 in FIG. 30) of calculating scores and a total
score of a plurality of items in the processing section 31 (score
calculation portion 311) of the swing diagnosis a